Zootaxa, Larval morphology of Rhantus Dejean, 1833 - CiteSeerX

Zootaxa 2317: 1–102 (2009) www.mapress.com / zootaxa/

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ZOOTAXA 2317

Larval morphology of Rhantus Dejean, 1833 (Coleoptera: Dytiscidae: Colymbetinae): descriptions of 22 species and phylogenetic considerations YVES ALARIE1, MARIANO C. MICHAT2, ANDERS N. NILSSON3, MIGUEL ARCHANGELSKY4 & LARS HENDRICH5 1

Department of Biology, Laurentian University, Ramsey Lake Road, Sudbury, Ontario, Canada. E-mail: [email protected] 2 CONICET Laboratorio de Entomología, DBBE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Av. Int. Güiraldes s/n, Ciudad Universitaria, 1428 Buenos Aires, Argentina. E-mail: [email protected] 3 Department of Ecology and Environmental Science, University of Umeå, Sweden. E-mail: [email protected] 4 CONICET-LIESA, Laboratorio de Investigaciones en Ecología y Sistemática Animal, Universidad Nacional de La Patagonia, San Juan Bosco, Sarmiento 849, 9200, Esquel, Chubut, Argentina. E-mail: [email protected] 5 Zoologische Staatssammlung, Münchhausenstraße 21, D - 81247 München, Germany. E-mail: [email protected]

Magnolia Press Auckland, New Zealand

Accepted by I. Ribera: 8 Oct. 2009; published: 22 Dec. 2009

Yves Alarie, Mariano C. Michat, Anders N. Nilsson, Miguel Archangelsky & Lars Hendrich LARVAL MORPHOLOGY OF RHANTUS DEJEAN, 1833 (COLEOPTERA: DYTISCIDAE: COLYMBETINAE): DESCRIPTIONS OF 22 SPECIES AND PHYLOGENETIC CONSIDERATIONS (Zootaxa 2317) 102 pp.; 30 cm. 22 Dec. 2009 ISBN 978-1-86977-439-4 (paperback) ISBN 978-1-86977-440-0 (Online edition)

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ALARIE ET AL.

Table of contents Abstract ............................................................................................................................................................................... 3 Introduction ......................................................................................................................................................................... 4 Material and methods .......................................................................................................................................................... 4 Description of the larvae of Rhantus Dejean, 1833 ............................................................................................................ 6 Key to species of instar I and III of the genus Rhantus ................................................................................................... 19 Description of larvae of Rhantus antarcticus nahueli Trémouilles, 1984 ................................................................. 23 Description of larvae of Rhantus anisonychus Crotch, 1873..................................................................................... 25 Description of larvae of Rhantus binotatus (Harris, 1828) ........................................................................................ 26 Description of larvae of Rhantus calidus (Fabricius, 1792) ....................................................................................... 27 Description of larvae of Rhantus calileguai Trémouilles, 1984 ................................................................................ 29 Description of larvae of Rhantus capensis (Aubé, 1838) .......................................................................................... 30 Description of larvae of Rhantus consputus (Sturm, 1834) ...................................................................................... 31 Description of larvae of Rhantus exsoletus (Forster, 1771) ....................................................................................... 32 Description of larvae of Rhantus fennicus Hulden, 1982 ......................................................................................... 34 Description of larvae of Rhantus frontalis (Marsham, 1802) .................................................................................... 35 Description of larvae of Rhantus grapii (Gyllenhal, 1808) ...................................................................................... 36 Description of larvae of Rhantus latitans Sharp, 1882 .............................................................................................. 37 Description of larvae of Rhantus notaticollis (Aubé, 1837) ...................................................................................... 38 Description of larvae of Rhantus orbignyi Balke, 1992 ............................................................................................. 40 Description of larvae of Rhantus phocaenarum Guignot, 1957 ................................................................................ 42 Description of larvae of Rhantus signatus (Fabricius, 1775) ..................................................................................... 46 Description of larvae of Rhantus simulans Régimbart, 1908 .................................................................................... 47 Description of larvae of Rhantus socialis (C. O. Waterhouse, 1876) ........................................................................ 48 Description of larvae of Rhantus suturalis (Macleay, W.S., 1825) ............................................................................ 49 Description of larvae of Rhantus suturellus (Harris, 1828) ....................................................................................... 50 Description of larvae of Rhantus validus Sharp, 1882 ............................................................................................... 52 Description of larvae of Rhantus wallisi Hatch, 1953 ............................................................................................... 53 Character Analysis ............................................................................................................................................................ 54 Discussion ......................................................................................................................................................................... 54 Acknowledgements ........................................................................................................................................................... 56 References ......................................................................................................................................................................... 56

Abstract Descriptions of larval instars of 22 species of Rhantus Dejean, 1833 are presented including a detailed chaetotaxic analysis of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi. A parsimony analysis including 25 Rhantus species (the 22 species described in this paper + 3 additional ones) from all major zoogeographic regions and representatives of other Colymbetini genera was conducted using the program TNT based on 43 informative larval characteristics. Jackknife values indicate strong support for the monophyly of members of the tribe Colymbetini (Colymbetinae), which is supported by eight synapomorphies. It is postulated that Rhantus is polyphyletic as Rhantus (Nartus) grapii (Gyllenhal, 1908) and R. monteithi Balke, Wewalka, Alarie & Ribera, 2007 occur as more closely related phylogenetically to other genera of the tribe Colymbetini than to the Rhantus species studied. We suggest that the Neotropical species R. orbignyi Balke, 1992, R. antarcticus nahueli Trémouilles, 1984, R. calidus (Fabricius, 1792) and R. validus Sharp, 1882 represent a distinct lineage within the Colymbetini. All these species diverge at the basis of the strict consensus trees prior to all other Colymbetini studied and are characterized by several unique larval character states. Larvae of Palearctic and Nearctic species of Rhantus were found to share similar character states, which is suggestive of a common phylogenetic origin. Key words: Dytiscidae, Colymbetini, Rhantus, larval morphology, chaetotaxy, phylogeny

LARVAE OF THE GENUS RHANTUS

Zootaxa 2317 © 2009 Magnolia Press ·

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Introduction The dytiscid genus Rhantus Dejean, 1833 is comprised of about 100 species worldwide (Nilsson 2001) and is represented in all major zoogeographic regions as well as on many oceanic islands. These beetles occur in shallow, plant-lined margins of pools and marshy areas (Zimmerman & Smith 1975). In term of classification, Rhantus is treated as a member of the subfamily Colymbetinae, which contains three tribes and 10 genera worldwide: Anisomeriini (Anisomeria Brinck, 1943, Senilites Brinck, 1948), Carabdytini (Carabdytes Balke, Hendrich & Wewalka, 1992) and Colymbetini (Rhantus, Bunites Spangler, 1972, Hoperius Fall, 1927, Melanodytes Seidlitz, 1887, Neoscutopterus J. Balfour-Browne, 1943, Colymbetes Clairville, 1806, Meladema Laporte, 1835) (Nilsson 2001). Due largely to the great diversity of the Colymbetinae, intergeneric relationships of members of the subfamily are not well known. Recent studies on larval morphology of these taxa, however, suggest a close phylogenetic relationship of Rhantus with members of Meladema and Neoscutopterus (Alarie & Hughes 2006; Michat 2005). Nilsson & Hilsenhoff (1991) and Ribera et al. (2008) postulated that Rhantus probably is not a natural group. Larval morphology of most Rhantus species is still poorly known. Worldwide, the larvae of 19 species have been described and/or figured, in most cases very superficially (Meinert 1901; Williams 1936; Bertrand 1928; Galewski 1963; Watts 1963; James 1969; Barman 1972; Nilsson 1987; Costa et al. 1988; Klausnitzer 1991; Alarie & Wang 2004; Balke et al. 2007). Except for R. fennicus Huldén, 1982 (Nilsson 1987), R. formosanus Kamiya, 1938 (Alarie & Wang 2004), R. monteithi Balke, Wewalka, Alarie & Ribera, 2007 and R. poellerbauerae Balke, Wewalka, Alarie & Ribera, 2007 (Balke et al. 2007), none of these descriptions used chaetotaxy as a diagnostic feature. Larval morphology is of great interest in the study of phylogenetic relationships of Holometabola. As different expressions of the same genotype, larval characters help to complement adult characters, which have been traditionally the primary basis for classification. Moreover, recent studies on larvae of Colymbetinae have indicated the usefulness of larval chaetotaxy (Alarie 1995, 1998; Alarie & Balke 1999; Alarie et al. 1998; Alarie & Hughes 2006; Michat 2005) both from a phylogenetic and diagnostic perspective. This paper is meant to be a step towards a better knowledge of the larval morphology of the genus Rhantus. It has the following goals: (1) descriptions of 22 species of Rhantus from all major zoogeographic regions with an emphasis on chaetotaxic analysis of the head capsule, cephalic appendages, legs, last abdominal segment and urogomphi and (2) analysis of the phylogenetic position of Rhantus within the Colymbetinae based on larval features.

Material and methods Larvae examined. Description of the larval stages and taxonomic conclusions reported in this paper are based on examination of larvae either found in association with adults or reared ex ovo (Alarie et al. 1989). Preparation. Larvae were disarticulated and mounted on standard glass slides with Hoyer's medium. Microscopic examination at magnification of 80–1000X was done using both an Olympus BX50 compound microscope equipped with Nomarsky differential interference optics and an Olympus CX31 compound microscope. Figures were prepared through use of a drawing tube attached to the microscope. Voucher specimens are deposited in the research collections of Y. Alarie and M.C. Michat. Descriptions. A complete description applying to all species is provided under the treatment of the genus, but only shorter diagnoses/descriptions and comments on variation are provided under the treatment of each species. Measurements. All measurements were made with a compound microscope equipped with a micrometer eyepiece. The part to be measured was adjusted so that it was, as nearly as possible, parallel to the plane of the objectives. The following measures were taken: Head length (HL): total head length including the frontoclypeus, measured medially along epicranial stem. Head width (HW): maximum head width. Length of


ALARIE ET AL.

frontoclypeus (FRL): from apex of nasale to posterior margin of ecdysial suture. Occipital foramen width (OCW): maximum width measured along dorsal margin of occipital foramen. Coronal line length (COL): measured along midline. Length of mandible (MN): measured from laterobasal angle to apex. Width of MN: maximum width measured at base. Length of antenna (A), maxillary (MP) and labial (LP) palpi were derived by adding the lengths of the individual articles; each article is denoted by the corresponding letter(s) followed by a number (e.g. A1: first antennomere; MP1: maxillary palpomere 1; LP1: labial palpomere 1). A3’ is used as an abbreviation for the apical lateroventral process of third antennomere. Length of galea (GA): measured along dorsal mid-line. Length of leg (L1–L3) including the longest claw: derived by adding the lengths of the individual articles. Length of trochanter includes only the proximal portion, the length of distal portion being included in the femoral length. Dorsal length of last abdominal segment (LLAS): measured along midline from anterior to posterior margin. Length of urogomphus (U): measured along outer margin. These measurements were used to calculate several ratios, which characterize body shape. Chaetotaxic analysis. Primary (observed in instar I) and secondary (added throughout the ontogenetic development) setae and pores were distinguished on the head capsule, head appendages, legs, last abdominal segment and urogomphus. The setae and pores were coded according to the system proposed by Alarie (1998) for the cephalic capsule and head appendages and Alarie (1995) for the last abdominal segment and urogomphus. Setae are coded by two capital letters corresponding to the first two letters of the name of the structure on which the seta is located (AB, last abdominal segment; AN, antenna; CO, coxa; FE, femur; FR, frontoclypeus; LA, labium; MN, mandible; MX, maxilla; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus) and a number. Pores are coded in a similar manner except that a lower case letter replaces the number. The position of the sensilla is described by adding the following abbreviations: A, anterior; AV, anteroventral; D, dorsal; Di, distal; Pr, proximal; PV, posteroventral. Instar I larvae of species of the genus Rhantus are characterized by the presence of additional setae (i.e., primary setae restricted to a genus or a tribe, which are not included in the ground-plan pattern of the Dytiscidae) on femora, tibiae and tarsi (Alarie 1995). These additional setae were included in the count of secondary setae owing to inter- and intraspecific variability. Colour. Description of colour is given from ethanol-preserved specimens unless otherwise stated. Parsimony analysis. Taxa were selected to give a broad overview of the morphological diversity found within Rhantus. All 22 Rhantus species (Table 1) of which the larvae have been described in the present work plus those, which have been described in detail in other works (R. formosanus, R. monteithi and R. poellerbaurae) were included in the ingroup. In order to examine the phylogenetic value of the characters observed on the larvae of Rhantus and to test the relationships of this genus with other genera of the tribe Colymbetini, a cladistic analysis was performed rooting the cladogram with representatives of other colymbetine genera and selected genera of the subfamily Agabinae (Agabus Leach, Ilybius Erichson, Ilybiosoma Crotch) as it has been suggested that Agabinae could represent the sister-group of the clade Colymbetinae + Lancetinae + Dytiscinae (Miller 2001). Species were used as terminals to avoid any assumption of monophyly of higher taxa. The characters used (Table 2) and the distribution of character states among the terminal taxa (Table 3) are listed. Apart from including the 43 informative characters we also have listed 15 autapomorphies. Although these features do not assist in the resolution of the relationships between taxa, they still represent important facies by which terminal groups (i.e. species) can be recognized. The phylogenetic relationships of Rhantus were analyzed cladistically using the program TNT (Goloboff et al. 2008). The tree was rooted in Agabus anthracinus Mannerheim, 1852 (Agabini), which was proposed to be closely related to Colymbetini (Miller 2001). All characters were treated as unordered and equally weighted. Multistate characters (characters 37, 38, 41, 46, 49, 50, 51) were treated as nonadditive. A heuristic search was implemented using ‘tree bisection reconnection’ as algorithm, with 200 replicates and saving 100 trees per replication (previously setting ‘hold 20000’). A second analysis was also performed with the same parameters, but using implied weighting (an a posteriori weighting) with the default options of TNT (K = 3). Bremer support values were calculated using the commands ‘hold 20000’, ‘sub n’ and ‘bsupport’, where ‘n’ is the number of extra steps allowed. The LARVAE OF THE GENUS RHANTUS


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process was repeated increasing the length of the suboptimal cladograms by one step, until all Bremer values were obtained (Kitching et al. 1998). Jackknife values were calculated with 2000 replicates and P (removal probability) = 36. TABLE 1. List of species of Rhantus of which larvae were studied; AF, Afrotropical; AU, Australian; NA, Nearctic; NT, Neotropical; OR, Oriental; PA, Pacific; PL, Palearctic. The species code and larval instar are indicated. Species

Distribution

Code

Instars

R. anisonychus Crotch, 1873

NA, NT

ANI

I

II

III

R. antarcticus nahueli Trémouilles, 1984

NT

ANT

I

II

III

R. binotatus (Harris, 1828)

NA

BIN

I

II

III

R. calileguai Trémouilles, 1984

NT

CAG

I

II

III

R. calidus (Fabricius, 1792)

NA, NT

CAL

I

II

III

R. capensis (Aubé, 1838)

AF

CAP

R. consputus (Sturm, 1834)

PL

CON

I

II

III

R. exsoletus (Forster, 1771)

PL

EXS

I

II

III

PL

FEN

I

II

III

R. formosanus Kamiya, 1938

PL

FOR

II

III

R. frontalis (Marsham, 1802)

PL

FRO

II

III

R. grapii (Gyllenhal, 1808)

PL

GRA

II

III

R. latitans Sharp, 1882

PL

LAT

III

R. monteithi Balke et al., 20072

PA

MON

III

R. notaticollis (Aubé, 1837)

PL

NOT

I

II

III

R. orbignyi, Balke, 1992

NT

ORB

I

II

III

AF

PHO

I

II

III

R. poellerbauerae Balke et al. 2007

PA

POE

R. signatus (Fabricius, 1775)

NT

SIG

R. simulans Régimbart, 1908

AU

SIM

R. socialis (C. O. Waterhouse, 1876)

AF

SOC

R. suturalis (Macleay, W.S.,1825)

AU, OR, PL

SUA

R. suturellus (Harris, 1828)

NA, PL

SUE

I

II

III

R. validus Sharp, 1882

NT

VAL

I

II

III

R. wallisi Hatch, 1953

NA

WAL

I

II

III

R. fennicus Huldén, 1982 1

R. phocaenarum Guignot, 1957 2

1

III

I

III I

II

III III

I

II

III III

Alarie & Wang (2004); 2 Balke et al. (2007)

Description of the larvae of Rhantus Dejean, 1833 Diagnosis. One important conclusion of this paper is that Rhantus is polyphyletic. It is therefore impossible to propose any diagnostic larval characters that may help at distinguishing members of Rhantus from other Colymbetini genera. Larvae of a majority of Rhantus species (19 of 24 species studied), however, differ from those of other Colymbetini by having urogomphus fractured proximally.


ALARIE ET AL.

TABLE 2. Characters used for the phylogenetic analysis and the coding of states using selected genera of Agabinae and Colymbetinae as outgroups. Character

States

Head capsule 01

Frontoclypeus (instar I)

0 – lacking additional setae 1 – with additional setae

02

Pore FRe (instar I)

0 – absent 1 – present

03

Parietale (instar I)


04

Occipital carina (instar I)

0 - lacking 1 - present

05

Frontoclypeus (instar I)

0 – at most extending at level of tip of adnasaliae 1 – extending beyond tip of adnasaliae

06

Adnasaliae (instar I, II, III)

0 – converging inward 1 – diverging outward

Head appendages 07

Antennomere I, pore ANg (instar I)

0 – proximal 1 – median to apical

08

Antennomere I (instar III)

0 – lacking secondary setae 1 – with secondary setae

09

Antennomere II (instar III)


10

Antennomere III, lateral projection (A3') 0 – finger-like (instar III) 1 – hole- to bulge-like

11

Antennomere III, ventroapical spinula 0 – present (instar I, II, III) 1 – absent

12

Antennomere III, additional ventroapical 0 – absent pores (instar I) 1 – present

13

Antenna (instar I)

0 – microspinulae absent 1 – microspinulae over most of its surface

14

Antennomeres 2– 4 (instar III)

0 – not fractured proximally 1 – fractured proximally

15

Maxillary palpus (instar III)

0 – less than 1.60 times length of labial palpus 1 – about 2.00 times length of labial palpus

16

Maxillary palpomere I (instar III)


17

Maxillary palpomeres 2– 3 (instar III)


18

Primary seta MX5 (instar I)

0 – short, much shorter than labial palpomere I 1 – elongate, longer than labial palpomere I

19

Stipes (instar I)

0 – lacking additional setae along inner margin 1 – with at least 1 additional seta along inner margin

20

Galea (instar III)

0 – short, ‹ 0.50 times length of maxillary palpomere 1 2 – elongate, › 0.70 times length of maxillary palpomere 1

21

Stipes (instar III)

0 – with short setae along inner margin 1 – with three elongate setae along inner margin continued next page



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TABLE 2. (continued) Character

States

22

Maxillary palpus (instar I)

0 – microspinulae lacking 1 – microspinulae over most of dorsal surface

23

Mandible, additional setae (instar I)

0 – absent 1 – present

24

Mandible (instar III)

0 – less than 3.40 times as long as broad 1 – more than 4.00 times as long as broad

25

Anterior margin of prementum (instar I, 0 – straight to shallowly emarginated II, III) 1 – deeply emarginated

26

Labial palpomere 2 (instar III)


27

Labial palpus (instar I)

0 – microspinulae lacking 1 – microspinulae over most of dorsal surface

28

Prementum AD primary setae (instar I, 0 – minute to short II, III) 1 – elongate

Legs 29

Procoxal seta CO7 (instar I)

0 – inserted more proximally, anterior to seta CO6 1 – inserted more distally, at about level of seta CO6

30

Metatrochanter (Instar III)

0 – with < 14 secondary setae 1 – with > 16 secondary setae

31

Trochanter (instar I)


32

Seta FE1 (instar I)

0 – inserted distally 1 – inserted proximally

33

Femur (instar I)

0 – lacking additional setae along dorsal margin 1 – with additional setae along dorsal margin

34

Mesofemoral seta FE5 (instar I)

0 – short and spine-like 1 – elongate and hair-like

35

Metafemoral seta FE5 (instar I)

0 – short, spine-like 1 – elongate and hair-like

36

Seta FE6 (instar I)

0 – short 1 – elongate

37

Protibia (instar I)

0 – additional setae absent 1 – additional setae on ventral margin only 2 – additional setae on dorsal and ventral margins

38

Mesotibia (instar I)

0 – additional setae absent 1 – additional setae on ventral margin only 2 – additional setae on dorsal and ventral margins

39

Seta TI6 (instar I)


40

Seta TI7 (instar I)


41

Tarsus (instar I)

0 – additional setae absent 1 – with 1 V additional seta 2 – with at least 2 V additional setae continued next page


ALARIE ET AL.

TABLE 2. (continued) Character

States

42

Metafemur (instar I)

0 – lacking PV additional setae 1 – with at least 1 PV additional seta

43

Tarsal claw basoventral microspinulae 0 – absent (instar I) 1 – present

44

Meso- and metatibial ventral marginal 0 – well developed spinulae (instar III) 1 – weakly developed or lacking

45

Meso- and metatarsal ventral marginal 0 – well developed spinulae (instar III) 1 – weakly developed or lacking

46

Legs, natatory setae (instar II and III)

0 – lacking 1 – on tibiae and tarsi 2 – on femora, tibiae, and tarsi

47

Abdominal segment 7 (instar 1)

0 – membranous ventrally 1 – sclerotized ventrally

48

Abdominal segment 8 (instar I)

0 – additional setae absent 1 – additional setae present

49

Urogomphus (instar III)

0 – subequal to HW 1 – < 0.80 times HW 2 – 1.20– 2.00 times HW 3 – > 2.00 times HW

50

Urogomphus outer margin (Instar II, III) 0 – lacking secondary setae 1 – with predominantly elongate hair-like setae 2 – with a variable number of spiniform and hair-like secondary setae 3 – with spiniform secondary setae only

51

Urogomphus inner margin (instar II, III) 0 – lacking secondary setae 1 – with secondary setae along outer margin only 2 – with secondary setae along both inner and outer margins

52

Urogomphus (instar III)


53

Urogomphus (instar I, II, III)

0 – two segmented 1 – one segmented

54

Urogomphus (instar I)

0 – at most with 1 additional seta 1 – with several additional setae

55

Primary seta UR2 (instar I)

0 – about as long as seta UR3 1 – longer than seta UR3

56


0 – shorter than setae UR5, UR6, UR8 1 – as long or longer than setae UR5, UR6, UR8

57


0 – articulated posterior to seta UR7 1 – articulated anterior to seta UR7

58


0 – shorter than setae UR5, UR6, UR8 1 – as long or longer than setae UR5, UR6, UR8

Abdomen

Urogomphus



9

TABLE 3. Distribution of 58 larval morphological characters among species. Character states are scored 0-3, ? (undetermined), - (inapplicable). Refer to Table 2 for character descriptions. Characters Taxon

1–5

6–10

11–15 16–20 21–25 26–30 31–35 36–40 41–45 46–50 51–58

Rhantus anisonychus Crotch

01011 01001 01100 00000 01000 01010 01011 11111

Rhantus antarcticus (Germain)

00011 01001 01000 00000 00000 00010 01000 10110 00100 20000 01100101

Rhantus binotatus (Harris)

01011 01001 01100 00000 01000 01000 01011 11111

11100 20022 21100000

Rhantus calileguai Trémouilles

01011 01001 01000 00000 00000 01010 01011 11111

11100 20022 21100000

Rhantus calidus (Fabricius)

00011 01001 01010 01010 10000 10110 01000 10010 00100 20010 00100010

Rhantus capensis Aubé

?????

01001 0??00 00?00 0??00 0?0?0 ?????

?????

11100 20022 21100000

???00

2??22 211?????

Rhantus consputus (Sturm)

01011 01001 01000 00000 00000 00010 01011 11111

11100 20001 21100100

Rhantus exsoletus (Forster)

01011 01001 01000 00010 00000 00010 01011 11111

11100 20021 21100100

Rhantus fennicus Huldén

01011 01001 01000 00000 00000 00000 01011 11111

21100 20001 21100100

Rhantus formosanus Kamiya

?????

01001 0??00 00?00 0??00 0?0?0 ?????

?????

???11

2??03 211?????

Rhantus frontalis (Marsham)

?????

01001 0??00 00?00 0??00 0?0?0 ?????

?????

???00

2??22 211?????

Rhantus grapii (Gyllenhal)

01000 11001 11000 00101 01000 01100 01111 11111

20111 20011 20101100

Rhantus latitans Sharp

?????

01001 0??00 00?00 0??00 0?0?0 ?????

?????

???00

2??01 211?????

Rhantus monteithi Balke et al.

?????

01001 0??00 00?00 0??00 0?0?0 ?????

?????

???10

2??11 1?1?????

Rhantus notaticollis (Aubé)

01011 01001 01000 00000 00000 00010 01011 11111

Rhantus orbignyi Balke

00011 01001 01000 00000 00000 00010 01000 10010 00100 20010 01100100

Rhantus phocaenarum Guignot

01011 01001 01000 00000 00000 00010 01011 11111

Rhantus poellerbauerae Balke et al. ?????

01001 0??00 00?00 0??00 0?0?0 ?????

?????

11100 20001 21100100 11100 20022 21100001 ???11

2??10 001?????

Rhantus signatus (Fabricius)

01011 01001 01000 00000 00000 00010 01011 11111

11100 20022 21100000

Rhantus simulans Régimbart

?????

???00

01001 0??00 00?00 0??00 0?0?0 ?????

?????

2??01 211?????

Rhantus socialis (C. O. Waterhouse) 01011 01001 01000 00000 00000 00000 01011 11?11 11110 20022 21100000 Rhantus suturalis (Macleay)

?????

01001 01?00 00?00 00?00 0?0?0 ?????

?????

???00

Rhantus suturellus (Harris)

01011 01001 01000 00000 00000 00010 01011 12211 21100 20001 21100100

Rhantus validus Sharp

00011 01001 01000 00010 10000 00110 01000 10011 00100 20011 2011????

Rhantus wallisi Hatch

01011 01001 01000 00000 00000 00010 01011 12211 21100 20001 21100100

Agabus anthracinus Mannerheim

00000 00000 00000 00010 00000 00000 00000 00000 00000 00000 0000----

Ilybiosoma seriatum Say

00000 00000 00000 00010 00000 00000 00000 00000 00000 00000 0000----

Ilybius angustior Gyllenhal

00000 00000 00000 00010 00000 00000 00000 00000 00000 00000 0000----

Colymbetes dolabratus (Paykull)

01011 01001 01000 00000 00000 00010 01000 10011 00100 10001 20100000

Melanodytes pustulatus (Rossi)*

01011 0?001 ???00

00?00 1?000 0?110 010?0 10011 011??

2??21 211?????

20011 20101101

Neoscutopterus hornii (Crotch)

11111

01001 11000 00000 00101 00011 01101 11111

21111 21111 2011????

Hoperius planatus Fall

?1???

01111 01?01 10?00 00?10 00010 ?????

??100 2??11 201?????

Meladema coriacea Laporte

11111

01001 01000 00010 00000 00011 01111 122?? 21111 20102 2011????

Meladema lanio (Fabricius)

11111

01001 01000 00010 00000 00011 11100 12201 21111 20103 2011????

Bunites distigma (Brullé)

11111

01??1 01?0? ??010 ??1?0

Carabdytes upin Balke et al.

?????

01001 0??00 00??0 0??00 0?0?1 ?????

??01?

?????

01000 12211 211?? ?????

???10

?01?? ??11???? 2??23 201?????

* From De Marzo (1974)

First-instar larva (Figs 1–14, 20–24, 30–34, 40–44, 51–55, 66–70, 76–80, 86–90, 101–106, 117–121, 127–131, 137–141, 147– 151, 162–166, 177–181, 187–195, 201–205)


ALARIE ET AL.

Colour. Some species predominantly yellowish, others brown to greyish brown; head either without or with colour pattern, remaining parts without colour pattern except for maculae variable in size and number on thoracic terga. TABLE 4. Number and position of additional setae on the legs of instar I of selected species of Rhantus Dejean; AD = anterodorsal, AV = anteroventral, FE = femur, PV = posteroventral, TA = tarsus, TI = tibia; n = number of specimens studied; acronyms as in Table 1. Species Segment ProFE

ProTI

ProTA

ANI (n= 3)

ANT (n= 2)

BIN CAG (n= 2) (n= 3)

CAL (n= 1)

CON (n= 1)

EXS FEN GRA (n= 2) (n= 1) (n= 1)

NOT (n= 1)

ORB (n= 2)

PHO (n= 1)

SIG (n=3)

SOC (n= 3)

SUT (n= 2)

VAL (n= 2)

WAL (n= 2)

AD 0

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

AV 1-2

5

3

1-2

1

4

5

5

2

3

4–5

3

2–3

1–2

3

3–4

4

PV 1

0

1

1

0

1

1

1

0

1

0

1

1

0–1

1

0–1

1

AD 0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

1

AV 2–3

0

1–2

1–2

0

2

2–3

3

3

2

0

2

2–3

1

2

0

2

PV 0

0

0

0

0

1

2

2

0

1

0

0

0

0

1

0

1–2

AV 1

0

1

1

0

1

1

1

2

1

0

1

1

1

1

0

1

PV 0

0

0

0

0

0

0

1

0

0

0

0

0

0

1

0

1

MesoFE AD 0

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

5

2–3

1

2

4

4–6

5

2

3

4–5

2

1–2

1–2

2–3

4–5

3

PV 1

0

0–1

1

0

1

1

1

0

1

0

1

1

1

1

0–1

1

AD 0

0

0

0

0

0

0

0

0

0

0

0

0

0–1

1

0

1

AV 2–3

1

2–3

2

0

2

3–4

4

3

2

0

3

2–3

2–3

3

0

3

PV 0

0

0

0

0

1

2

2

0

1

0

0

0

0

1

0

1–2

MesoTA AV 1

0

1

1

0

1

1

1

3

1

0

1

1

1

1

0

1

PV 0

0

0

0

0

0

0

1

0

0

0

0

0

0

1

0

1

AD 0

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

AV 1–2

5

2

1–2

2

3

4

4

2

2

4–5

3

1–3

1

4

3–4

4

PV 1

0

1

1

0

1

1

1

0

1

0

1

1

1

1

0

1

AV 1–2 MesoTI

MetaFE

MetaTI

AD 0

0

0

0

0

0

0

0

0

0

0

0

0

0–1

1

0

1

AV 2

1

2

2

0

3

4

3

4

3

0

3

2–3

2

3

0

3

PV 0

0

0

0–1

0

1

2

2

0

1

0

0

0

0

1

0–1

1

MetaTA AV 1

0

1

1

0

1

1

1

2

1

0

1

1

1

1

0

1

PV 0

0

0

0

0

0

0

1

0

0

0

0

0

0

1

0

1

Body. Subcylindrical. Head. Head capsule (Figs 1–2, 20, 30, 40, 51, 66, 76, 86, 101, 117, 127, 137, 147, 162, 177, 187, 201). HL = 0.85–1.40 mm; HW = 0.78–1.44 mm; FRL = 0.38–0.67 mm. Flattened, subovate to subtrapezoidal, about as broad as long (HL/HW = 0.88–1.13), maximum width at level of stemmata, constricted or not at level of occipital region; occipital foramen variable in width, HW/OCW = 1.44–2.55, deeply emarginate ventrally; ecdysial suture well-developed, coronal suture short, 0.46–0.59 times HL; occipital suture present, lightly or strongly impressed; frontoclypeus subtriangular, lateral margins curved, apical margin convex mesally, extending at about level or beyond apex of lateral lobes [= adnasaliae], FRL/HL = 0.42–0.54, with one spinelike egg burster on each side (= ruptor ovi of Bertrand 1972), apical margin with 15–35 lamellae clypeales (Bertrand 1972) variable in shape (spiniform, digitiform or spatulate) and size; six stemmata, four on upper side of head and two on underside, arranged in two convex vertical series; tentorial pits visible ventrally on each side of middle at about midlength; frontoclypeus and parietale covered with microspinulae or not. Antenna (Figs 3–4). Slender, either shorter or longer than HW (A/HW = 0.65–1.37); A1 the shortest, A4 the longest or subequal to A3 (A4/A3 = 0.83–1.31); A3 with a ventroapical spinula present or lacking; apical



11

TABLE 5. Number of secondary setae1 on the legs of instar II of selected species of Rhantus Dejean (acronyms as in Table 1). A = anterior, AD = anterodorsal, AV = anteroventral, CO = coxa, D = dorsal, Di = distal, FE = femur, NS = natatory setae, PD = posterodorsal, Pr = proximal, PV = posteroventral, TA = tarsus, TI = tibia, TR = trochanter, V = ventral, n = number of specimens studied, Total = total number of secondary setae on segment. Segment

Sensillar ANI ANT BIN CAG series (n = 2) (n = 2) (n = 2) (n = 3)

CAL (n = 2)

CON EXS (n = 1) 2 (n = 2)

FEN GRA NOT FOR3 FRO 2 (n = 1) (n = 3) (n = 1) 2 (n = 2) (n = 1) 2

ProCO

D

5–6

7–10

3–9

7

4–6

A

5–6

4–6

2–4

3–5

4–5

3–4

3

4–5

5–7

3–4

5

4–5

V

3–4

3

3

3–6

2–4

3–5

4–5

3

2–3

4–5

6–9

4–5

Total

14–15

15–19

13–15

13–17

10–17

14–15

13–14

11–14

19–22 12–13

20–22

15–16

Pr

1

1–3

1

0–1

0

0–1

1

1

1

3

0

Di

0

0

0

0–1

0

0

0

0–1

0

0

1

0

Total

1

1–3

1

0–1

0

0

1

1–2

1

0

4

0

NS (PD) 13– 15 27– 28 15– 18 15– 18

24– 33

17– 19

17

14– 17

13– 17 12– 17 10– 11 16– 17

AD

8

9–11

8–10

8–14

5–9

8–12

11–14

11–13

8–11

AV

7–8

7–9

9–10

7–10

8–11

10–13

14–15

20–22

PD

0

0

0

0

0

0

0

0

PV

4–6

6–7

6–8

6–8

4–6

6–8

8–9

Total

34–35

49–55

38–46

39–47

47–53

44–49

51–54

ProTR

ProFE

ProTI

ProTA

MesoCO

MesoTR

MesoFE

MesoTI

8

5–8

6

12

4–5

8–9

0

8

6–7

14–16

11–12

12–13 5–6

19–25

13–14

0

0

0–1

0

11

8–9

6–7

13–14

9

56–63

26–31 32–37

60–63

50–51

NS (PD) 14–15

22–23

15–16

15–18

27–33

21

15–17

13–18

15–18 15–17

10

14–16

AD

2–3

1

2

3–5

2–3

5–6

4–6

2–3

3–4

3

2–3

2–3

AV

4–5

3–4

4–6

3–4

10–12

6–8

7

7

4–6

5

9–11

6

PV

3–5

3–4

4

2–4

2

5–6

5

6–7

3–4

3–4

7–9

3–4

Total

25–26

29–32

26–27

26–27

41–50

39

31–35

30–33

26–31 27–32

28–33

26–28

NS (PD) 11–12

12–14

13–14

14–16

22–24

17–18

14–15

13–14

14–15 14

8–10

14–15

AD

2

0

2

2

2–3

2–3

2

2

2–3

2

1

1–2

AV

4–6

3–4

4–5

4–5

9–10

6–8

6

5

6

4–5

7–8

5–6

PV

0–1

3

0

0

0

3–4

3–4

5–7

2

1

6–7

3

Total

19

18–21

18–20

20–23

34–36

28–30

25–27

25–28

24–26 19–22

23–25

24–25

D

5

8–10

6–8

4–6

5–7

5–6

4–5

5

8–10

5

7

5–8

A

3–4

4–7

2–4

4

3–4

3

3–4

3–4

4–5

3

7

2–4

6

V

4–5

3–5

3

3–7

3

3–4

4–5

4–5

2–4

7–12

5–6

Total

12–14

17–21

13

11–16

11–14

11–13

12–13

12–14

16–18 14

21–26

15

Pr

1

2–3

1

0

0

0

1–2

1–2

1

0

5–7

0

Di

0

0–1

0

0–1

0

0

0

0

0

0

1–2

0

Total

1

0

2–3

1

0–1

0

0

1–2

1–2

1

6–9

0

NS (PD) 12

23–25

13–14

14

21–29

15–16

12–15

15–18

14–17 11–13

8–9

14–15

AD

9–10

11–12

10–13

10–15

8–9

9–11

10–16

15

12–13 7–9

16–17

13–14

AV

9

10–12

11–12

9–13

13

17–20

17–18

17

11–12

6–9

18–19

12–13

7–8

PV

7

8–10

6–7

6–10

6–8

6–7

7–8

10

8–10

13–16

8–9

Total

37–38

52–59

41–45

42–47

48–59

41–49

48–55

57–60

45–52 34–36

56–60

48–50

NS (PD) 13–17

26–28

16–17

17–20

31–36

19–22

18–19

18–19

15–20 18

11–14

16–18

AD

3–5

3–4

4

6–8

6

5–6

6

5

5

5

5

4

AV

7–8

5–8

8–9

4–9

11–12

11–14

9–11

10–11

8–9

8–9

11–12

7–9

PV

5–6

4–5

4

3–7

3–4

5–8

4–6

6–7

3

3

7–8

4

Total

29–35

38–45

32–34

34–39

52–57

41–49

39–40

40–41

31–37 34–35

34–39

33

continued next page


ALARIE ET AL.

TABLE 5. (continued) Segment MesoTA

MetaCO

MetaTR

MetaFE

MetaTI

MetaTA

1

Sensillar ANI ANT BIN CAG series (n = 2) (n = 2) (n = 2) (n = 3)

CAL (n = 2)

CON EXS (n = 1) 2 (n = 2)

FEN GRA NOT FOR3 FRO 2 (n = 1) (n = 3) (n = 1) 2 (n = 2) (n = 1) 2

NS (PD) 15–16

19

15–16

16–21

22–31

20

15–20

16–19

15–18 17–20

14–15

17

AD

2

1

2–7

2–3

2–3

4

3–4

2

3–4

2

1

2–3

AV

6–7

5–7

6–8

5–7

11–13

9–11

9–11

6–8

6–8

6–7

9–10

7

PV

3–4

3–5

2

1–3

0

5

5

6–8

3

3

7–8

4

Total

27–28

28–32

27–31

25–33

35–47

38–40

33–39

30–37

28–31 28–32

32–33

30–31

D

3

5–7

5–6

3–5

3

4–5

3–4

6

5–7

3

5

5–6

A

2–3

4–7

2–3

3–5

2–4

4

5

5

3–5

4

7

2–4

V

3–6

3–5

3

4–6

2–3

2–3

4–5

3–4

5–6

5–6

7–11

6–7

Total

9–11

15–19

11

12–16

7–10

10

13

14–15

15–17 12–13

19–23

14–16

Pr

1

1–6

1

0–1

0–1

0

2

1–2

1–2

0

5

1

Di

0

1–2

0

0–1

0

0

0

0

0

0

1–2

0–1

Total

1

3–7

1

0–1

0–1

0

2

1–2

1–2

0

6–7

1–2

6

NS (PD) 5

8–9

5–6

1–4

8–10

6–8

3–5

4–5

6–8

3–4

5–7

AD

9–11

13–16

11

10–16

9–10

12–15

13–17

11–14

12–13 9–10

21–24

14–13

AV

8–9

9–11

10

6–10

7–10

12–15

11–14

9–16

11–13

7–8

17–19

11–16

PV

7

8–13

5–6

6–8

5–6

4–6

5–6

9–10

7

7

13

7

Total

29–32

38–49

31–33

23–33

29–36

39

35–39

36–42

36–41 30

55–59

38–42

NS (PD) 15–17

24–26

19–20

19–20

25–32

18–20

20

18

15–17 20–21

11–12

16–18

AD

5–7

5

5

5–10

5–6

7–8

8–9

7

6

7–8

9–10

6–7

AV

9–10

8

10–11

7–10

9–11

11–14

8–12

9

7–8

9–10

11

8–10

3–4

PV

3–5

4–5

2–3

3–6

3

5

5

5

3–4

7–8

4

Total

33–38

41–44

36–39

39–43

42–52

42–45

41–46

39

32–35 41

38–41

34–39

NS (PD) 16–18

23–24

17–18

18–23

25–32

24

21

22

17

19–21

15–16

19–20

AD

2–3

1–3

2–4

3–4

5–6

3

4

4

3–5

4

4

3

AV

6–7

6–8

8–9

7–9

9–11

10–11

11–13

9

6–8

8–9

10–11

9

PV

4–5

4–6

2

2–3

3

4

4

5

1–3

2–3

7–9

3–4

Total

29–32

34–41

29–32

32–35

42–52

41–42

40–42

40

27–32 35

38

35

including additional setae, cf. material and methods; 2 both legs included; 3 Alarie & Wang (2004).

lateroventral process of A3 not protruding. Mandible (Fig. 9). Prominent, falciform, wide at base, sharp apically, 2.11–3.00 times as long as broad, 0.52–0.72 times as long as HL; mandibular channel present, pubescence developed along inner margins. Maxilla (Figs 5–6, 102, 192–193). Cardo small, narrow; stipes well developed, subtrapezoidal, either without or with a few microspinulae along inner margin; palpifer short, broad, palpomere-like, 0.20–0.44 times as long as MP1; palpus 3-segmented (A/MP = 1.27–1.76), MP1 the shortest, MP3 the longest and narrowest (MP3/MP2 = 1.05–1.60); galea well developed, subconical (GA/ MP1 = 0.43–1.28). Labium (Figs 7–8, 194–195). Prementum subrectangular, broader than long, anterior margin straight to shallowly emarginate, with microspinulae on dorsal surface; palpus 2-segmented, elongate, slender (MP/LP = 0.94–1.25); palpomeres subequal in length or LP2 somewhat longer than LP1 (LP2/LP1 = 0.85–1.34). Thorax. Terga convex, lateral margins curved; pronotum about as long as meso- and metanotum combined, meso- and metanotum subequal; sagittal line visible; tergites subrectangular, transversal, margins rounded, protergite more developed than the others, meso- and metatergite with anterotransverse carina; venter membranous; spiracular openings absent. Legs (Figs 10–11, 21–22, 31–32, 41–42, 52–53, 67–68, 77– 78, 87–88, 103–104, 118–119, 128–129, 138–139, 148–149, 163–164, 178–179, 188–189, 202–203). Long,



13

6-segmented (sensu Lawrence 1991); L3 the longest, L1 the shortest; L3 = 2.38–4.16 mm; L3/HW = 2.54– 3.43; CO robust, elongate, TR subdivided into 2 parts, FE, TI and TA slender, subcylindrical; two long, slender, slightly curved claws, posterior claw shorter than anterior one on L1 and L2, anterior claw either shorter than or subequal to posterior one on L3; claws with basoventral spinulae; legs covered with microspinulae more or less developed; FE, TI and TA with a row of ventral spinulae variably developed. Abdomen. 8-segmented; segments I–VII sclerotized dorsally, membranous ventrally, progressively narrowing to apex; sagittal line visible on segments I–III or I–IV; tergites I–VI similar to each other, narrow, transverse, laterally rounded, with anterotransverse carina; segment VII somewhat longer, with anterotransverse carina; spiracular openings absent on segments I–VII; LAS (Figs 12–13, 23, 33, 43, 54, 69, 79, 89, 105, 120, 130, 140, 150, 165, 180, 190, 204) variable in size, short to very elongate, completely sclerotized, ring-like, without anterotransverse carina (LAS = 0.51–1.00 mm, LAS/HW = 0.58–0.99), covered with densely distributed microspinulae; siphon reduced. Urogomphus (Figs 14, 24, 34, 44, 55, 70, 80, 90, 106, 121, 131, 141, 151, 166, 181, 191, 205). One-segmented, variable in length (U = 0.84–1.83 mm, U/LAS = 0.87–3.12, U/HW = 0.80–1.87), with microspinulae either on whole surface or only at about basal 1/2. Chaetotaxy. First-instar larvae of Rhantus present the following characteristics and differences with the generalized Colymbetinae larva (Alarie 1995, 1998; Alarie & Hughes 2006): FR with 15–35 more or less developed setae on anterior margin, arranged in a single row, pore FRe either present (Figs 20, 30, 51, 66, 76, 86, 101, 117, 137, 147, 162, 177, 201) or absent (Figs 1, 40, 127, 187), seta FR8 elongate (Figs 1, 20, 30, 40, 51, 66, 76, 86, 101, 117, 127, 137, 147, 162, 177, 187, 201); two additional pores on ventral surface of A3 (Fig. 4); seta MN1 inserted either more or less distally (Fig. 9); pore MXa absent (Figs 5–6); spine-like setae on anterodorsal surface of prementum either very short (Fig. 7) or elongate (Fig. 194), prementum with a variable number of additional spine-like setae on anterodorsal surface (Figs 7, 194), LP2 with 1–2 minute structures near setae LA10 and LA12; presence of a variable number of additional setae on legs (Table 4); setae FE6 and TI6 elongate and setiform (Figs 11, 22, 32, 42, 53, 68, 78, 88, 104, 119, 129, 139, 149, 164, 179, 189, 203); seta FE5 on meso- and metafemur either moderately elongate and spiniform (Figs 11, 42, 129, 189) or very elongate and setiform (Figs 22, 32, 53, 68, 78, 88, 104, 119, 139, 149, 164, 179, 203); seta TI7 either short and spiniform (Figs 11, 42, 129) or elongate and setiform (Figs 22, 32, 53, 68, 78, 88, 104, 119, 139, 149, 164, 179, 189, 203); U with one additional, minute, apical seta, and either without (Figs 14, 24, 34, 44, 55, 70, 80, 90, 106, 121, 131, 141, 151, 166, 181, 205) or with (Fig. 191) numerous additional long setae; primary seta UR4 either shorter than any of setae UR5, UR6, or UR8 (Figs 24, 34, 44, 55, 141, 151, 166) or elongate, subequal in length to any of setae UR5, UR6, or UR8 (Figs 14, 70, 80, 90, 106, 121, 131, 181, 205); seta UR5 either articulated posteriorly (Figs 14, 24, 34, 55, 70, 80, 90, 106, 121, 131, 141, 151, 166, 181, 205) or anteriorly (Fig. 44) to seta UR7. Second-instar larva As first instar except as follows: Colour. Some species predominantly yellowish, others light brown to brown or almost black; head, thoracic and abdominal tergites either without or with colour pattern, remaining parts without colour pattern. Head. HL = 1.32–2.28 mm; HW = 1.25–2.20 mm; FRL = 0.60–1.02 mm. Head capsule. Subquadrate, parallel sided (HL/HW = 0.88–1.16, HW/OCW = 1.47–2.11); COL/HL = 0.54–0.59; FR/HL 0.33–0.48; egg bursters lacking. Antenna. Shorter to slightly longer than HW (A/HW = 0.55–1.12); A1 the shortest, remaining segments subequal or A2 and A3 the longest (A4/A3 = 0.70–1.20). Mandible. 2.42–3.09 times as long as broad, 0.45–0.65 times as long as HL. Maxilla. PPF/MP1 = 0.25–0.45, A/MP = 1.29–1.85; either MP2 or MP3 the longest (MP3/MP2 = 0.78–1.41); GA/MP1 = 0.29–0.95. Labium. MP/LP = 0.96–1.43; LP1 either longer or somewhat shorter than LP2 (LP2/LP1 = 0.79–1.10). Thorax. Legs. L3 = 3.85–6.06 mm, L3/HW = 2.55–3.17; all legs without microspinulae, or L2 and L3 with microspinulae on dorsal surface of CO.


ALARIE ET AL.

TABLE 6. Number of secondary setae1 on the legs of instar II of selected species of Rhantus Dejean (acronyms as in Table 1). A = anterior, AD = anterodorsal, AV = anteroventral, CO = coxa, D = dorsal, Di = distal, FE = femur, NS = natatory setae, PD = posterodorsal, PV = posteroventral, Pr = proximal, TA = tarsus, TI = tibia, TR = trochanter, V = ventral, n = number of specimens studied, Total = total number of secondary setae on segment. Segment ProCO

ProTR

ProFE

ProTI

ProTA

MesoCO

MesoTR

MesoFE

MesoTI

Sensillar series

ORB (n = 3)

PHO (n = 2)

SIG (n = 3)

SOC (n = 2)

SUT (n = 2)

VAL (n = 1) 2

WAL (n = 2)

D

5–6

5–6

3–6

7

8–9

11–13

6–7

A

4

2

2–4

5–7

2–4

5

4

V

0–1

3–4

2–6

6–7

3–5

2–3

4

Total

9–10

11

8–10

18–21

15–16

19–20

14–15

Pr

0–1

0

0

0

0

2

0

Di

0

0–1

0

0

0

0

0

Total

0–1

0–1

0

0

0

2

0

NS (PD)

10–17

13–19

11–13

18–19

14–15

14–15

18

AD

8–11

11

6–9

7–9

12–13

13–15

10–11

AV

8–12

10–14

6–8

9–10

10–12

14–16

14

PV

6–8

8

4–7

8–9

8

9–10

8

Total

33–45

46–48

27–30

43–46

45–47

52–54

50–51

NS (PD)

8–15

17–18

10–13

14–18

15–16

12

18

AD

1

2–3

3

2–4

3–5

5–6

3–4

AV

2–4

5–7

2–4

4–5

5

4–6

4–6

PV

2–3

3–5

2–4

3

4–5

8–9

4

Total

13–22

29–31

18–21

24–29

28–30

30–32

30–31

NS (PD)

7–9

15–16

9–11

13

13–15

12–13

16

AD

0

2–3

2

2

2

3–5

2

AV

2–4

6

3–4

5

6

4–5

5

PV

0

0

0

0

4

5–6

3

Total

9–12

24

15–17

20

25–27

26–27

26

D

6–7

5–6

3–4

7–8

5–7

9–11

5–6

A

4–5

2–3

2–3

3–4

3–4

4–7

3–4

V

1–4

3–5

2–4

4–7

5–7

4–7

3–4

Total

11–14

12

8–10

15–18

15–16

20–22

12–13

Pr

1

0–2

0

0

1

4–5

0

Di

0

0

0

0

0–1

0–1

0

Total

1

0–2

0

0

1–2

5

0

NS (PD)

9–14

13–15

7–9

15–17

11–12

13–14

12–16

AD

7–14

12–13

6–9

11–13

10–11

17

7–12

AV

11–14

9–14

7–12

7–9

13–14

13–17

12

PV

7–9

9

4–6

9–10

7–8

8–9

8

Total

40–46

46–48

26–34

45–46

42–44

53–55

39–48

NS (PD)

12–16

18–19

12–14

18–19

16–17

13

17

AD

2–3

5

3–5

5–6

5–6

9

4–5

AV

4–6

9–11

6–7

7

7–8

7–10

8–9

PV

3

5

2–4

4

4–6

8

4

Total

23–26

38–39

26–28

35

33–36

37–40

33–35 continued next page



15

TABLE 6. (continued) Segment MesoTA

MetaCO

MetaTR

MetaFE

MetaTI

MetaTA

1

Sensillar series

ORB (n = 3)

PHO (n = 2)

SIG (n = 3)

SOC (n = 2)

SUT (n = 2)

VAL (n = 1) 2

WAL (n = 2)

NS (PD)

11–12

17–19

14

18–19

16–17

16–17

17–20

AD

0–1

3–4

2–3

3

2

7

2

AV

5–6

8–9

5–8

6–8

7–8

8–9

6–8

PV

0

2

0–2

3

4

7–8

5

Total

16–18

32

21–27

31–32

29–31

38–41

32–33

D

3–5

3–5

2–3

4–5

4–6

5–6

4–5

A

2–4

1–3

0–2

3–5

2–3

6

4

V

1–4

3–6

2–4

5–6

2

5

4

Total

7–14

9–12

5–8

13–15

9–10

16–17

12–13

Pr

1

0–1

0

0

0–1

4

0–1

Di

0–1

0

0

0

0

0

0

Total

1–2

0–1

0

0

0–1

4

0

NS (PD)

2–6

5–8

1–2

9–10

4

3–4

7

AD

10–14

14–15

7–10

13

14–15

17–21

13–15

AV

11–13

10–13

6–8

8–9

11

14–15

9–10

PV

7–10

9–13

4–7

8–9

6

9

6–7

Total

32–40

42–45

20–21

39–40

35–36

43–44

37

NS (PD)

14–16

18–23

13–15

20

16–17

14–15

17–19

AD

3–5

6–10

4–6

9

6

12

5–6

AV

6–8

9–10

6–8

6–8

8–6

7–10

8–9

PV

0–2

6–8

1–3

4–5

3–6

9

3

Total

27–30

41–49

24–29

40–41

33–39

43–45

34–36

NS (PD)

15–19

22–24

16–18

21–22

17–19

20–21

22–24

AD

1–2

4–5

2–3

4

2

9

4

AV

6–8

11–12

6–9

8

8

10

8–9

PV

0

3

1–2

3–4

2–4

8–9

3–4

Total

23–27

41–43

26–30

37

31

47–49

37–47

including additional setae, cf. material and methods; 2 both legs included.

Abdomen. Sagittal line visible on segments I–VI; segment VII completely sclerotized, ring-like, with anterotransverse carina dorsally and laterally; LAS with anterotransverse carina (LAS = 1.03–2.18 mm, LAS/ HW = 0.66–1.37). Urogomphus. Fractured proximally (as in Figs 19, 29, 39, 60, 65, 85, 95, 100, 126, 136, 146, 156, 161, 171, 176, 186, 210) or not (as in Figs 50, 75, 111, 116, 195); U = 0.91–2.70 mm, U/LAS = 0.44–2.39, U/HW = 0.57–1.69; either without microspinulae or with microspinulae basally. Chaetotaxy. Head capsule with several secondary pores and hair-like setae; FR with 32–88 lamellae clypeales along apical margin, arranged in a double row; PA with 3–13 temporal spine-like setae posterior to stemmata; MN with several minute secondary setae on dorsal, ventral and external margins; number and position of leg secondary setae represented in Tables 5–6; natatory setae on posterodorsal margin of FE, TI and TA (on metafemur restricted to distal 1/3 to 2/3) (as in Figs 17, 27, 37, 48, 58; 63, 73, 83, 93, 98, 109, 114, 124, 134, 144, 154, 159, 169, 174, 184, 198, 208); LAS with several hair-like and/or spine-like secondary setae (except medially on ventral surface) (as in Figs 18, 28, 38, 49, 59, 64, 74, 84, 94, 99, 110, 115, 125, 135, 145, 155, 160, 170, 175, 185, 199, 209); U either without secondary setation (as in Figs 19, 50, 136), or with numerous spine-like and/or hair-like secondary setae (as in Figs 29, 39, 60, 65, 75, 85, 95, 100, 111, 116, 126, 146, 156, 161, 171, 176, 186, 200, 210).


ALARIE ET AL.

TABLE 7. Number of secondary setae1 on the legs of instar III of selected species of Rhantus Dejean (acronyms as in Table 1). A = anterior, AD = anterodorsal, AV = anteroventral, CO = coxa, D = dorsal, Di = distal, FE = femur, NS = natatory setae, PD = posterodorsal, PV = posteroventral, Pr = proximal, TA = tarsus, TI = tibia, TR = trochanter, V = ventral, n = number of specimens studied, ns = non–available, Total = total number of secondary setae on segment. Segment Sensillar ANI series (n= 3)

ANT (n= 3)

BIN (n = 3)

CAG (n= 3)

CAL (n = 3)

CAP CON EXS (n = 1) 2 (n = 1) 2 (n = 2)

FEN GRA FOR3 FRO (n = 2) (n = 6) (n = 1) 2 (n = 2)

ProCO

10–13

11–18

12–22

14–15

15–18 15–19

ProTR

ProFE

ProTI

ProTA

D

8–11

17–20

A

6–8

17–20

7–9

6–11

5–6

8

5–6

7–10

11–18

4–9

9–10

7–10

V

3–4

4–5

2–3

4–7

3–4

6

5

4–5

5

3–4

4–5

7

Total

18–22

41–43

21–22

22–30

21–31

28–29

22–24

21–27

31–41 24–27

27–29

28–33

10–12

13–15

14–16

Pr

2–4

4–7

2–4

2–4

1

2–3

3–4

2–4

4–6

1–2

2–3

4–5

Di

0

0–1

0

0

0

0

0

0

0

0

0

1–2

Total

2–4

4–7

2–4

2–4

1

2–3

3–4

2–4

4–6

1–2

2–3

5–7

NS (PD) 29–37

59–60

25–30

34–39

56–62

29

38–42

27–31

33–36 26–28

33–35

15–17

AD

8–12

9–12

10–13

14–18

6–8

11–13

11–12

12–14

13

9–12

17

AV

17–21

8–10

13–18

14–18

13–15

20–21

21–22

18–24

31–33 18–19

17–19

23–24

PD

0

0

0

0

0

0

0

0–1

0

0

0

PV

8–11

7–10

12–14

7–11

6–8

7–10

13–15

10–13

15–17 7–11

9–11

17–18

Total

62–81

11–13 0

83–92

62–75

70–83

81–92

67–73

85–89

67–83

95–96 64–69

72–73

73–75

NS (PD) 27–35

39

24–25

30–33

52–63

26–27

33–34

24–28

27–29 25–26

28–30

12–16

AD

2–3

1

2–3

3–5

6–8

3

5–6

2–3

3

2–4

3

2–4

AV

5–7

3–5

3–5

2–5

10–12

6–7

8–9

5

6–7

5

6

11–12

PV

3–5

3–4

3–4

2–4

3–4

4

6

5–7

7

4

5

7–8

Total

38–47

46–49

34–35

40–44

67–81

40

50–55

36–43

43–46 37–41

42–44

36

NS (PD) 19–23

20–22

18–20

24–27

44–50

19–20

26–31

19–23

21

21–24

22–23

9–12

AD

2

0

2

2–3

2

2

3

2

1–2

2–3

1–2

1

AV

5–6

3–4

5

4–6

10–12

5

7–9

5–6

4–7

5–6

5

6–8

PV

0–1

3–4

0

0

0

0

3–4

2–4

6–7

1–2

1–2

7–8

Total

27–31

26–30

25–26

24–27

56–64

26–27

41–45

28–35

33–36 31–32

30–31

24–28

MesoCO D

8–10

17–24

12–19

13–16

13–20

14–15

14

7–9

13–17 12–14

13–16

12–13

A

5–8

18–25

8–9

4–10

5–8

7–10

5–8

8–11

12–18 7–14

10

10–13

V

4

3–7

3–5

5–10

2–6

6

4–5

4–6

5–6

5–6

6–10

Total

18–20

43–51

25–31

24–32

20–31

27–31

24–26

19–26

34–37 28–31

29–31

28–36

4–5

4–7

4–7

3–4

1

2–3

3–5

3–4

5–7

2–3

2–3

8–9

Di

0

0–1

0

0–1

0

0

0

0

0

0

0

1–3

Total

4–5

4–7

4–7

3–5

1

2–3

0

3–4

5–7

2–3

2–3

9–10

52–59

25–30

32–35

50–65

28–29

33–34

20–27

28–32 23–24

24–28

13

MesoTR Pr

MesoFE NS (PD) 26–33

MesoTI

12–13

4–7

AD

10–12

12–14

14–19

15–19

7–9

14–15

13–16

14–17

13–15 12–14

13

18

AV

15–19

10–12

15–19

11–15

10–14

16–18

26–29

17–24

24–26 12–14

19–21

19–23

PD

0

0

0

0

0

0

0–1

0

0

0

0

0

PV

11–16

9–12

14–18

11–14

7

13–16

16–19

11–14

6–7

11–12

15

15–17

Total

63–80

83–97

68–86

70–81

74–93

73–76

92–95

68–82

84–93 60–61

73–75

65–71

NS (PD) 30–35

44–50

27–33

37–44

64–71

32–35

39–42

32

31–34 27–31

30–32

16–18

AD

4–5

3–4

5–6

6–8

3–5

6–7

7

4–7

5

6

6–7

4

AV

7–11

7–8

8–9

6–8

14–17

9

16

10–12

9–11

6–9

10

11–12

PV

4–5

4–6

4–7

2–4

4

5–6

7–9

6

6–7

3–5

5

8–9

Total

46–55

58–68

45–53

55–65

85–97

53–56

69–74

54–55

54

43–50

51–54

40–42

continued next page



17

TABLE 7. (continued) Segment Sensillar ANI series (n= 3)

ANT (n= 3)

BIN (n = 3)

CAG (n= 3)

CAL (n = 3)

CAP CON EXS (n = 1) 2 (n = 1) 2 (n = 2)

FEN GRA FOR3 FRO (n = 2) (n = 6) (n = 1) 2 (n = 2)

MesoTA NS (PD) 26–29

30–31

25–27

33–41

53–56

28–30

34–38

28–31

27–31 26–29

29–30

17–19

2–3

2–3

2–4

2–3

3–4

2–3

2

2

2

2

0–1

3

AV

7–8

6–7

8–9

7–9

12–15

7–8

11

9–11

7–8

7–8

7–8

7

PV

2–4

4–5

1–2

2–4

0

2–4

6

4

6–7

2–3

2–3

7

Total

38–42

40–44

37–39

46–57

68–74

39–45

53–59

43–49

43–47 39–42

41–42

33–36

MetaCO D

7–9

17–24

12–13

10–13

8–10

9–13

11–12

8–10

15–21 10–13

10–12

11–13

A

4–7

21–26

9–15

6–8

5–8

8–9

9–10

7–11

13–18 7–9

10–13

12–14

V

2–5

3–7

2–5

4–10

1–7

7–8

3–4

3–4

4

3–5

7–10

Total

13–19

45–49

24–33

20–29

14–24

25–29

23–26

18–25

32–43 23–27

26–27

32–35

Pr

3–5

4–6

3–5

3–5

1–2

2–4

3–4

5–6

6–8

3–4

8

Di

1

1–2

0

0–1

0

0

0

0–1

0

0

0–1

2–4

Total

3–5

4–6

3–5

3–5

1–2

2–4

3–4

5–7

6–8

2–3

4

10–12

NS (PD) 7–13

24–25

10–15

11–16

29–34

14

13–15

7–8

7–14

12–13

11–12

2–4

AD

12–15

13–16

13–18

16–23

6–7

16–17

16–19

14–17

17–18 15–18

16–17

20–22

AV

13–18

11–13

13–18

10–15

9–15

15–18

20–28

18–22

16–24 12–13

19–21

17

MetaTR

MetaFE

MetaTI

MetaTA

1

AD

5–6 2–3

PV

10–16

9–12

15–19

11–15

6–9

14

15

12–15

14–18 10–13

14

18–21

Total

45–62

57–66

51–69

54–65

51–62

60–62

69–72

54–59

56–58 49–59

62

59–62

48

29–32

41–43

55–66

32–36

39–41

30–31

32

28–31

17

NS (PD) 29–36

27–28

AD

7

4–6

7–9

10–11

4–7

8–9

10–14

7–9

8–9

8–10

9–10

7

AV

5–7

9–12

8–10

7–12

11–16

10–11

17–18

10–11

10

8–9

9–10

11

3–4

PV

4–6

4–7

4–6

4–6

2–5

4–5

6–7

6

6–7

4

10

Total

48–61

65–73

50–55

54–59

74–81

54–61

73–79

55

56–58 48–49

52–53

45

NS (PD) 29–34

38–39

26–29

41–42

42–55

34–37

41–42

33–35

34–35 30–31

28–30

21–24

AD

2–4

2

2–3

2–6

2–3

4

3

3

3

4–5

3–4

4

AV

8

8–10

10

7–11

11–13

9–10

11–13

9–11

10

9

10–11

10–12

PV

1–5

4–6

2–3

2–6

0

3

6

4–5

5–6

2–3

1–3

8–10

Total

41–51

52–57

42–44

54–59

56–71

51–53

62–63

51–52

52–54 46–47

43–47

43–50

2

3

Including additional setae, cf. material and methods; both legs included; Alarie & Wang (2004).

Third-instar larva (Figs 15–19, 25–29, 35–39, 45–50, 56–65, 71–75, 81–85, 91–100, 107–116, 122–126, 132–136, 142–146, 152–161, 167–171, 172–176, 181–186, 196–201, 206–210). As second-instar larva except as follows: Colour. Some species predominantly yellowish to light brown, others reddish to dark yellow or light brown to brown. Head (Figs 15, 25, 35, 45, 56, 61, 71, 81, 91, 96, 107, 112, 122, 132, 142, 152, 157, 167, 172, 182, 196, 206). HL = 2.10–3.75 mm; HW = 1.85–4.28 mm; FRL = 0.85–1.44 mm. Either as long or longer than broad (HL/HW = 0.88–1.30), sides either subparallel with maximum width at stemmata, or slightly converging anteriorly with maximum width posterior to stemmata; HW/OCW = 1.41–2.25; ecdysial line clearly visible or difficult to see in darker species (COL/HL = 0.50–0.65); FR/HL = 0.35–0.48; microspinulae reduced to lacking. Antenna. A2, A3 and A4 fractured proximally (Fig. 46) or not; A/HW = 0.50–0.93; either A3 or A4 the shortest (A4/A3 = 0.63–1.20). Mandible. 2.42–3.43 times as long as broad, 0.44–0.62 times as long as HL. Maxilla. MP2 and MP3 fractured proximally or not; PPF/MP1 = 0.24–0.43, A/MP = 1.24–1.74; MP1 and


ALARIE ET AL.

MP2 subequal in length, MP3 slightly shorter or longer (MP3/MP2 = 0.69–1.21); GA/MP1 = 0.32–0.81. Labium. LP2 fractured proximally or not; MP/LP = 0.99–1.43; LP1 longer than LP2 (LP2/LP1 = 0.62–0.87). Thorax. Protergite subquadrate, strongly convex but turning to concave on laterals; spiracular openings present on mesothorax. Legs (Figs 16–17, 26–27, 36–37, 47–48, 57–58, 62–63, 72–73, 82–83, 92–93, 97–98, 108–109, 113–114, 123–124, 133–134, 143–144, 153–154, 158–159, 168–169, 173–174, 183–184, 197–198, 207–208). L3 = 5.42–10.01 mm, L3/HW = 2.24–2.94; legs without microspinulae or with microspinulae on dorsal surface of CO. Abdomen. Sagittal line visible on segments I–VI or I–VII; segment VII with anterotransverse carina; spiracular openings present on segments I–VII; LAS (Figs 18, 28, 38, 49, 59, 64, 74, 84, 94, 99, 110, 115, 125, 135, 145, 155, 160, 170, 175, 185, 199, 209) = 1.33–3.68 mm, LAS/HW = 0.62–1.53. Urogomphus (Figs 19, 29, 39, 50, 60, 65, 75, 85, 95, 100, 111, 116, 126, 136, 146, 156, 161, 171, 176, 186, 200, 210). U = 0.85–3.70 mm, U/LAS = 0.24–2.23, U/HW = 0.35–1.51. Chaetotaxy. FR with 60–90 spatulate setae on apical margin; PA with 6–16 temporal spine-like setae posterior to stemmata; position and number of leg secondary setae as represented in Tables 7–8; U either without secondary setation (Figs 19, 50, 136) or with numerous spine-like and/or hair-like secondary setae (Figs 29, 39, 60, 65, 75, 85, 95, 100, 111, 116, 126, 146, 156, 161, 171, 176, 186, 200, 210).

Key to species of instar I and III of the genus Rhantus In addition to the species described in this paper, this key of identification includes R. formosanus, R. monteithi and R. poellerbauerae, which were described recently with much details, including chaetotaxy (Alarie & Wang 2004; Balke et al. 2007). 1. 2.

-

3.

-

4.

-

Frontoclypeus with two egg bursters (cf., Fig. 1); legs lacking natatory setae; spiracles lacking (instar I) ................ 2 Frontoclypeus smooth, lacking egg bursters; legs with natatory setae along dorsal margin of femora, tibiae and tarsi (cf., Fig. 17); spiracles lacking (instar II) or present (instar III) ............................................................................... 18 Adnasaliae diverging outward (Fig. 101); galea elongate, longer than length of maxillary palpomere I (Fig. 102); cranium not constricted at level of occiput (Fig. 101); primary setae MX5 and MX7 longer than length of galea (Fig. 102); femora with at least 1 dorsal additional seta (Fig. 103); primary seta UR2 longer than seta UR3 (Fig. 106); antennomere III lacking a ventroapical spinula; antennomere IV > 1.50 times as long as antennomere III; maxillary palpomere III > 1.60 times as long as maxillary palpomere II; urogomphi subequal in length to length of last abdominal segment; occipital carina lightly impressed (Fig. 101) ..................................................................R. grapii Adnasaliae converging inward (e.g., Fig. 1); galea shorter, less than 0.70 times as long as length of maxillary palpomere I (Figs 5–6); cranium at least slightly constricted at level of occiput (e.g., Fig. 1); primary setae MX5 and MX7 shorter than length of galea (Fig. 6); femora lacking dorsal additional seta (e.g., Figs 10–11); primary seta UR2 subequal in length to seta UR3 (e.g., Fig. 14); antennomere III with a ventroapical spinula (Fig. 4); antennomere IV < 1.30 times as long as antennomere III; maxillary palpomere III < 1.50 times as long as maxillary palpomere II; urogomphi subequal or distinctly longer than length of last abdominal segment; occipital carina well defined (e.g., Fig. 1) ............................................................................................................................................................................ 3 Meso- and metafemoral primary seta FE5 short and spine-like (Figs 11, 42, 129, 189); protibia and each tarsus lacking additional setae; metafemur lacking posteroventral additional setae (Figs 11, 42, 129, 189); primary pore FRe absent (Figs 1, 40, 127, 187) ................................................................................................................................ 4 Meso- and metafemoral primary seta FE5 elongate and hair-like (e.g., Fig. 22); protibia and each tarsus with at least one additional seta (e.g., Fig. 21); metafemur with at least 1 posteroventral additional seta (e.g., Fig. 22); primary pore FRe present (e.g., Fig. 20).................................................................................................................................... 7 Urogomphus with several additional setae (Fig. 191); anterodorsal marginal primary setae of prementum elongate (Fig. 194); primary seta TI7 elongate and hair-like (Fig. 189); microspinulae present over most of dorsal surface of parietale; primary seta MX5 elongate, longer than length of palpifer (Fig. 192); microspinulae present over most surface of urogomphi ..................................................................................................................................... R. validus Urogomphus at most with one additional seta (e.g., Fig. 14); anterodorsal marginal primary setae of prementum minute (Fig. 7); primary seta TI7 short and spine-like (Figs 11, 42, 129); microspinulae present at most over



19

5.

-

6.

-

7. 8.

-

9. 10.

-

11. 12. 13 14. -

15.

-

posterior 2/3 of dorsal surface of parietale; primary seta MX5 short, shorter than length of palpifer (Fig. 5); microspinulae restricted to basal 1/2 of urogomphi .................................................................................................... 5 Urogomphus slightly shorter than length of last abdominal segment; frontoclypeus extending mesally at about level of tip of adnasaliae, with less than 14 lamellae clypeales (Fig. 40); stipes with one additional seta along inner margin; microspinulae over posterior 2/3 of dorsal surface of parietale; antennomere III lacking additional ventroapical pores; primary seta UR5 articulated anteriorly to seta UR7 (Fig. 44); femora with less than 2 anteroventral additional setae (Fig. 41); metathoracic legs < 2.60 times HW; smaller species, HL < 0.90 mm ........... ......................................................................................................................................................................... R. calidus Urogomphus longer, > 1.30 times length of last abdominal segment; frontoclypeus extending mesally well beyond adnasaliae, with more than 15 lamellae clypeales (Figs 1, 127); stipes lacking additional seta along inner margin; microspinulae at most over posterior 1/2 of dorsal surface of parietale; antennomere III with additional ventroapical pores (Fig. 4): primary seta UR5 articulated posterior to seta UR7 (Figs 14, 131); femora with 4 or more anteroventral additional setae (Figs 10, 128); metathoracic legs > 2.90 times HW; larger species, HL > 1.10 mm... 6 HW/OCW < 1.80; antenna < 0.70 times as long as HW; mesotibia with at least one additional seta; primary seta UR7 slightly shorter than any of setae UR5, UR6, UR8 (Fig. 14); frontoclypeus with more than 27 lamellae clypeales; tarsal microspinulae over basal 2/3 to 3/4 ...................................................................................R. antarcticus nahueli HW/OCW > 2.00; antenna > 0.80 times as long as HW; mesotibia lacking additional setae; primary seta UR7 about 1/2 as long as any of setae UR5, UR6, UR8 (Fig. 131); frontoclypeus with less than 16 lamellae clypeales; tarsal microspinulae more reduced, covering at most basal 1/2 ............................................................................. R. orbignyi Antennae, maxillary and labial palpomeres densely covered with microspinulae ...................................................... 8 Antennae, maxillary and labial palpomeres smooth, lacking microspinulae............................................................... 9 Microspinulae lacking over dorsal surface of frontoclypeus; microspinulae present over posterior 2/3 of dorsal surface of parietale; procoxal seta CO7 articulated distally to articulation of seta CO6; labial palpomere II > 1.10 times as long as labial palpomere I; frontoclypeus with more than 24 lamellae clypeales ...................R. anisonychus Microspinulae present over most of dorsal surface of frontoclypeus and parietale; procoxal seta CO7 articulated proximally to articulation of seta CO6; labial palpomere II < 1.00 times as long as labial palpomere I; frontoclypeus with less than 20 lamellae clypeales ........................................................................................................... R. binotatus Microspinulae present over most of dorsal surface of parietale ................................................................................ 10 Microspinulae present at most over posterior 1/2 of dorsal surface of parietale ........................................................ 13 Microspinulae present at most over proximal 1/2 of urogomphi; primary seta UR4 as long or longer than any of setae UR5, UR6, UR8 (Fig. 121); last abdominal segment longer, about 0.90 times as long as HW; urogomphi about 1.70 times as long as last abdominal segment; Palearctic ............................................................................... R. notaticollis Microspinulae present over entire surface of urogomphi; primary seta UR4 distinctly shorter than any of setae UR5, UR6, UR8 (Figs 55, 141, 166); last abdominal segment shorter, < 0.70 times as long as HW; urogomphi > 2.30 times as long as last abdominal segment: Afrotropical, Neotropical ................................................................................... 11 Lamellae clypeales spatulate; procoxal seta CO7 articulated proximally to articulation of seta CO6 ........ R. socialis Lamellae clypeales spiniform or digitiform; procoxal seta CO7 articulated distally to articulation of seta CO6 ..... 12 Tarsal claws with marginal spinulae over basal 2/3 to 3/4; Afrotropical............................................. R. phocaenarum Tarsal claws with marginal spinulae restricted to basal 1/2 or less; Neotropical ...................................... R. calileguai Pro- and mesotibiae with at least one dorsal additional seta, with microspinulae over most of anterior surface; tarsal claws with marginal spinulae over basal 2/3 to 3/4; Nearctic..................................................................................... 14 Pro- and mesotibiae lacking dorsal additional setae; microspinulae restricted to dorsal margin of coxae and ventral margin of femora; tarsal claws with marginal spinulae restricted to basal 1/2 or less; Neotropical, Palearctic ....... 15 Antenna < 1.10 times as long as HW and < 1.60 times as long as length of maxillary palpus; metathoracic legs < 2.90 times as long as HW; profemur with 3 anteroventral additional setae; body colour yellowish grey . R. suturellus Antenna > 1.20 times as long as HW and > 1.70 times as long as length of maxillary palpus; metathoracic legs > 3.10 times as long as HW; profemur with 4 anteroventral additional setae; body colour predominantly greyish black ......................................................................................................................................................................... R. wallisi Primary seta UR4 shorter than any of setae UR5, UR6, UR8 (Fig. 151); tibiae lacking posteroventral additional setae (Fig. 149); pro- and mesofemora with at most 3 anteroventral additional setae; antennomere IV < 1.00 times as long as HW; maxillary palpomere III > 1.30 times as long as maxillary palpomere II; smaller species, HL < 0.90 mm; Neotropical.................................................................................................................................................... R. signatus Primary seta UR4 subequal or longer than any of setae UR5, UR6, UR8 (Figs 70, 80, 90); tibiae with at least 1 posteroventral additional seta (Figs 68, 78, 88); pro- and mesofemora with at least 4 anteroventral additional setae;


ALARIE ET AL.

16.

-

17.

-

18. 19.

-

20.

-

21.

-

22.

-

23 -

antennomere IV > 1.10 times as long as HW; maxillary palpomere III < 1.20 times as long as maxillary palpomere II; larger species, HL > 1.10 mm; Palearctic .............................................................................................................. 16 Stipes with at least 1 additional seta along inner margin; urogomphi > 2.00 times as long as length of last abdominal segment, with microspinulae over proximal 1/2; antennae > 1.30 times as long as HW; mandible < 2.50 times as long as broad; metathoracic legs > 3.30 times as long as HW .................................................................. R. exsoletus Stipes lacking additional setae along inner margin; urogomphi < 1.70 times as long as length of last abdominal segment, with microspinulae over the entire surface; antennae < 1.10 times as long as HW; mandible > 2.60 times as long as broad; metathoracic legs < 3.20 times as long as HW .................................................................................. 17 Lamellae clypeales spatulate; procoxal seta CO7 articulated proximally to articulation of seta CO6; tarsi with at least 2 ventral additional setae (Figs 87–88); antenna about 1.30 times as long as maxillary palpus; antennomere IV > 1.80 times as long as antennomere I and > 1.20 times as long as antennomere III; mandible about 3.0 times as long as broad ......................................................................................................................................................... R. fennicus Lamellae clypeales spiniform or digitiform; procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; tarsi with at most one ventral additional seta (Figs 67–68); antenna about 1.60 times as long as maxillary palpus; antennomere IV < 1.50 times as long as antennomere I and < 1.00 times as long as antennomere III; mandible about 2.70 times as long as broad ..............................................................................................R. consputus Urogomphi lacking secondary setae (Figs 19, 50, 136)............................................................................................. 19 Urogomphi with secondary setae (e.g., Fig. 29) ........................................................................................................ 22 Stipes with 3 elongate hook-like spiniform setae along inner margin; lamellae clypeales spiniform to digitiform; antennomeres II–IV (Fig. 46), maxillary palpomeres II–III and labial palpomere I fractured proximally (best seen under compound microscope); abdominal segment 8 elongate, > 1.30 times as long as HW; urogomphus short, < 0.30 times as long as last abdominal segment; protarsus with > 40 natatory setae; Nearctic/Neotropical ... R. calidus Stipes with only minute setae along inner margin; lamellae clypeales spatulate; antennomeres II–IV, maxillary palpomeres II–III and labial palpomere I not fractured proximally; abdominal segment 8 shorter, < 1.20 times as long as HW; urogomphus longer, > 0.70 times as long as last abdominal segment; protarsus with < 30 natatory setae ..................................................................................................................................................................................... 20 HW/OCW > 2.20; antennomere IV < 0.50 times as long as antennomere I; mandible > 3.30 times as long as broad; last abdominal segment shorter, < 0.70 times as long as HW; profemoral, meso- and metatibial and meso- and metatarsal AV marginal spinulae weakly developed; metathoracic legs < 2.40 times as long as HW; metatibia with > 9 PV secondary setae; urogomphi not fractured proximally; Pacific ................................................ R. poellerbauerae HW/OCW < 1.60; antennomere IV > 0.90 times as long as antennomere I; mandible < 3.00 times as long as broad; last abdominal segment longer, > 1.00 times as long as HW; profemoral, meso- and metatibial and meso- and metatarsal AV marginal spinulae strongly developed; metathoracic legs > 2.80 times as long as HW; metatibiae with < 7 AV secondary setae; urogomphi fractured proximally (Figs 19, 136); Neotropical............................................ 21 Stipes lacking microspinulae along inner margin; antenna about 1.60 times as long as maxillary palpus; mesofemur with < 40 natatory setae; meso- and metatarsi lacking PV secondary setae; metatibia with < 40 natatory setae; smaller species, HL < 2.90 mm .................................................................................................................... R. orbignyi Stipes with microspinulae along inner margin; antenna about 1.40 times as long as maxillary palpus; mesofemur with > 50 natatory setae; meso- and metatarsi with at least 4 PV secondary setae; metatibia with > 45 natatory setae; larger species, HL > 3.10 mm .....................................................................................................R. antarcticus nahueli Galea elongate, about 0.80 times as long as maxillary palpomere I; adnasaliae diverging outward (Fig. 107); most anterior secondary temporal spine-like setae articulated at about level of occipital region (Fig. 107); antennomere III lacking a ventroapical spinula; maxillary palpomere III > 1.10 times as long as maxillary palpomere II; metathoracic legs about 3.30 times as long as HW; mesofemur with < 15 natatory setae; metatibia with < 20 natatory setae; Palearctic.......................................................................................................................................................... R. grapii Galea shorter, < 0.50 times as long as maxillary palpomere I; adnasaliae converging inward (e.g., Fig. 25); most anterior secondary temporal spine-like setae articulated at about level of ocularium (e.g., Fig. 25); antennomere III with a ventroapical spinula; maxillary palpomere III < 1.00 times as long as maxillary palpomere II; metathoracic legs < 3.00 times as long as HW; mesofemur with > 20 natatory setae; metatibia with > 22 natatory setae............. 23 Outer margin of urogomphi with elongate hair-like setae only, except for one short spine-like seta proximally (Figs 75, 85, 95, 116, 126, 161, 176, 186 200, 210) ............................................................................................................ 24 Outer margin of urogomphi with a variable number of hair-like and spine-like setae (Figs 29, 39, 60, 65, 100, 146, 156, 171) .................................................................................................................................................................... 34



21

24. Inner margin of urogomphi lacking secondary setae; last abdominal segment < 0.70 times as long as HW; antennomere IV about 0.60 times as long as antennomere I; maxillary palpus about 1.40 times as long as labial palpus; HW/OCW about 2.10; metathoracic legs about 2.30 times as long as HW; meso- and metatibial and metatarsal marginal spinulae weakly developed, almost lacking; mesofemur with > 30 PV secondary setae; mesotarsus with > 12 PV secondary setae; metafemur with > 40 D spine-like secondary setae; larger species, HL = 3.80 mm; Pacific ......................................................................................................................................... R. monteithi - Inner margin of urogomphi with secondary setae; last abdominal segment > 0.90 times as long as HW; antennomere IV > 0.70 times as long as antennomere I; maxillary palpus < 1.20 times as long as labial palpus; HW/OCW < 2.00; metathoracic legs > 2.50 times as long as HW; meso- and metatibial and metatarsal marginal spinulae strongly developed; mesofemur with < 20PV secondary setae; mesotarsus with < 8 PV secondary setae; metafemur with < 30 D spine-like secondary setae; smaller species, HL < 3.50 mm ................................................................................. 25 25. Dorsal secondary setae of coxae predominantly short (Figs 83, 93, 114, 174), if not, metafemoral natatory setae articulated over distal 2/3 to 3/4 of dorsal margin; Palearctic .................................................................................... 26 - Dorsal secondary setae of coxae predominantly elongate (Figs 73, 159, 184, 198, 208); metafemoral natatory setae articulated over distal 1/2 of dorsal margin Australian, Nearctic, Neotropical, Palearctic ........................................ 30 26. Antenna < 1.30 times as long as maxillary palpus; mandible > 3.20 times as long as broad; profemur with > 30 AV and > 15 PV secondary setae (Figs 92–93); mesofemur with < 8 PV secondary setae .............................. R. fennicus - Antenna > 1.60 times as long as maxillary palpus; mandible < 3.00 times as long as broad; profemur with < 28 AV and < 13 PV secondary setae (Figs 82–83, 113–114, 123–124); mesofemur with > 10 PV secondary setae ........... 27 27. Urogomphi shorter, < 0.80 times as long as last abdominal segment ............................................................R. latitans - Urogomphi longer, > 1.00 times as long as last abdominal segment ......................................................................... 28 28. Antenna > 0.90 times as long as HW; urogomphi > 1.30 times as long as HW......................................... R. exsoletus - Antenna < 0.80 times as long as HW; urogomphi < 1.20 times as long as HW......................................................... 29 29. HL > 2.60 mm; urogomphus > 2.70 mm; L3 > 6.90 mm; A4/A1 > 0.90; tarsi with PV secondary setae; protrochanter with > 3 secondary setae .......................................................................................................................... R. notaticollis - HL < 2.50 mm; urogomphus < 2.50 mm; L3 < 6.20 mm; A4/A1 < 0.80; tarsi lacking PV secondary setae; protrochanter with 1 secondary seta .............................................................................................................R. suturalis 30. Stipes with 3 elongate hook-like setae along inner margin; prementum with elongate setae along anterior margin (e.g., Fig. 194); antenna < 1.30 times as long as HW; profemoral anteroventral marginal spinulae weakly developed, almost lacking (Fig. 197); urogomphus not fractured proximally (Fig. 200); meso- and metacoxae with > 50 secondary setae; trochantera with > 7 secondary setae; pro- and metatibiae with > 8 PV secondary setae; larger species, HL = 3.50 mm; Neotropical ............................................................................................................. R. validus - Stipes with 2–3 minute setae along inner margin; prementum with minute setae along anterior margin (e.g., Fig. 7); antenna > 1.50 times as long as HW; profemoral anteroventral marginal spinulae strongly developed (e.g., Fig. 207); urogomphus fractured proximally (e.g., Fig. 210); meso- and metacoxae with < 40 secondary setae; trochantera with < 6 secondary setae; pro- and metatibiae with < 7 PV secondary setae; smaller species, HL < 3.00 mm; Australian, Nearctic, Palearctic ........................................................................................................................ 31 31. Microspinulae present along inner margin of stipes; meso- and metatarsi lacking PV secondary setae; Australian ..... ..................................................................................................................................................................... R. simulans - Microspinulae lacking along inner margin of stipes; meso- and metatarsi with > 3 PV secondary setae; Nearctic, Palearctic.................................................................................................................................................................... 32 32. Pro-, meso- and metatibia with > 33, 39 and 39 natatory setae, respectively; mesofemur with > 26 AV secondary setae; meso- and metatibiae with > 15 and 17 AV secondary setae, respectively; Palearctic ...................R. consputus - Pro-, meso- and metatibia with < 29, 35 and 33 natatory setae, respectively: mesofemur with < 20 AV secondary setae; meso- and metatibiae with < 10 and 12 AV secondary setae, respectively; Nearctic or Holarctic .................. 33 33. Protarsus with < 21 natatory setae (Fig. 184); meso- and metafemur with < 27 and 9 natatory setae, respectively; metatibia with < 28 natatory setae; body predominantly black ................................................................. R. suturellus - Protarsus with > 23 natatory setae (Fig. 208); meso- and metafemur with > 29 and 12 natatory setae, respectively; metatibia with > 31 natatory setae; body predominantly yellowish ............................................................... R. wallisi 34. Outer margin of urogomphus with spine-like secondary setae only; metatarsal ventral spinulae weakly developed, almost lacking; metathoracic legs < 2.50 times as long as HW; Palearctic............................................. R. formosanus - Outer margin of urogomphus with a variable number of spine-like and hair-like secondary setae (e.g., Fig. 65); metatarsal ventral spinulae strongly developed (e.g., Fig. 62); metathoracic legs > 2.60 times as long as HW; African, Nearctic, Neotropical, Palearctic ................................................................................................................. 35


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35. Afrotropical species .................................................................................................................................................... 36 - Nearctic, Neotropical, Palearctic species ................................................................................................................... 38 36. Urogomphi < 1.40 times as long as last abdominal segment; lamellae clypeales spiniform to digitiform; profemoral ventral spinulae well-developed (Fig. 62); metafemur with natatory setae over distal 3/4 of dorsal margin; last abdominal segment about 0.90 times as long as HW .................................................................................. R. capensis - Urogomphi > 1.85 times as long as last abdominal segment; lamellae clypeales spatulate; profemoral ventral spinulae weakly developed, almost lacking (Figs 143, 168); metafemur with natatory setae at most over distal 1/2 of dorsal margin; abdominal segment < 0.70 times as long as HW ............................................................................... 37 37. Microspinulae present along inner margin of stipes; meso- and metatibial ventral spinulae weakly developed or lacking; profemur with < 14 AV secondary setae (Fig. 168); metatibia with < 9 AV secondary setae ......... R. socialis - Microspinulae lacking along inner margin of stipes; meso- and metatibial ventral spinulae strongly developed; profemur with > 21 AV secondary setae (Fig. 143); metatibia with > 11 AV secondary setae ............R. phocaenarum 38. Last abdominal segment longer, about 1.20 times as long as HW; Palearctic ............................................ R. frontalis - Last abdominal segment shorter, < 1.00 times as long as HW; Nearctic, Neotropical .............................................. 39 39. Profemoral and metatibial ventral spinulae weakly developed or lacking (Fig. 57); mesofemur with > 50 natatory setae; metatibia with > 40 natatory setae; Neotropical .............................................................................. R. calileguai - Profemoral and metatibial ventral spinulae strongly developed; mesofemur with < 35 natatory setae; metatibia with < 36 natatory setae ..................................................................................................................................................... 40 40. Microspinulae present along inner margin of stipes; protibia with > 27 natatory setae (Fig. 27); Nearctic/Neotropical ................................................................................................................................................................ R. anisonychus - Microspinulae lacking along inner margin of stipes; protibia with < 25 natatory setae (Figs 37, 154) .................... 41 41. Metafemur with > 15 PV secondary setae; Nearctic................................................................................... R. binotatus - Metafemur with < 11 PV secondary setae; Neotropical ............................................................................. R. signatus

Description of larvae of Rhantus antarcticus nahueli Trémouilles, 1984 Source of material. The larvae studied were both reared ex ovo and collected in association with adults at the following localities. Argentina, Chubut Province. 1) Aldea Escolar, Laguna Seca (INTA experimental station), 450 masl, 3.XI.2003; 2) stream arising from Laguna La Z, surroundings of Esquel City, 2003, M. Archangelsky & M.C. Michat, leg. First-instar larva (n = 6) (Figs 1–14) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Dorsal surface of cephalic capsule dark brown except for one light brown macula enclosing each egg burster; ventral surface dark brown except for a narrow, longitudinal, light brown band centrally; head appendages brown except for distal 1/2 of mandible yellowish; thoracic and abdominal tergites brown; legs brown except for coxa somewhat paler and medial portion of trochanter testaceous; urogomphus brown. Head (Figs 1–9). Head capsule (Figs 1–2). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae reduced, covering posterior 1/2 of dorsal surface. Antenna (Figs 3–4). Microspinulae lacking, antennomere III with a ventroapical spinula. Maxilla (Figs 5–6). Palpus lacking microspinulae. Labium (Figs 7–8). Palpus lacking microspinulae. Thorax. Legs (Figs 10–11). Microspinulae restricted to dorsal margin of coxae and ventral margin of femora, tibiae and tarsi; tarsal claws with microspinulae covering basal 3/4 of ventral margin. Abdomen. Urogomphus (Fig. 14). Microspinulae reduced, almost lacking. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe lacking (Fig. 1); anterior margin of frontoclypeus with 27–31 spiniform to digitiform lamellae clypeales (Fig. 1); A3 with two additional ventroapical pores (Fig. 4); primary seta MX7 shorter than galea (Fig. 6); primary seta MX5 shorter than palpifer and galea (Fig. 5); stipes lacking additional setae along inner margin (Figs 5– 6); anterodorsal primary setae of prementum minute (Fig. 7); procoxal seta CO7 articulated distally, at about level of seta CO6; meso- and metafemoral seta FE5 short and spine-like (Fig. 11); seta TI7 short and spineLARVAE OF THE GENUS RHANTUS


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like (Fig. 11); urogomphus (Fig. 14) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 as long as any of setae UR5, UR6 or UR8; seta UR5 articulated posteriorly to articulation of seta UR7; seta UR7 as long as any of setae UR5, UR6 or UR8. Second-instar larva (n = 6) As first-instar larva except as follows: Colour. Dorsal surface of cephalic capsule dark brown dorsally except for one dorsal, light brown macula posterior to each lateral margin of frontoclypeus; head appendages brown except for distal 1/2 of mandible reddish brown; urogomphus light brown. Head. Maxilla. Microspinulae lacking along inner margin of stipes. Thorax. Legs. Anteroventral spinulae strongly developed on profemora, tibiae and tarsi; metacoxa with several elongate hair-like secondary setae along dorsal margin (cf. Fig. 17); metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 19). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 5; parietale with 8–9 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 18); urogomphus lacking secondary setae (cf. Fig. 19). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 6) (Figs 15–19) As second-instar larva except as follows: Colour. Dorsal surface of cephalic capsule light brown except for several small lighter maculae on central portion of frontoclypeus, posterior to stemmata, anterior to occipital suture and medial to each ocular area (Fig. 15); head appendages light brown except for distal 1/2 of mandible reddish; thoracic and abdominal tergites light brown; membranous parts testaceous; legs light brown; urogomphus yellowish. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 7 (Figs 16–17); parietale with 8–9 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Larvae of this Neotropical species are characterized by the following unusual features in Rhantus: absence of primary pore FRe (best seen in first instar) (Fig. 1), short and spine-like condition of meso- and metafemoral primary setae FE5 and TI7 (first instar) (Fig. 11), absence of additional setae on protibiae and tarsi (first instar) (Table 4), and absence of secondary setae on urogomphus (Fig. 19). Such combination of characters is found in only two other species of Rhantus, namely R. calidus (Fabricius, 1792) and R. orbignyi. It is noteworthy that all these three species are found in the Neotropical region. Larvae of R. antarcticus nahueli can readily be distinguished from the other two species of this group by the following combination of characters: larger size, absence of microspinulae along inner margin of stipes (second- and third instars), number of PV secondary setae on meso- and metatarsi and natatory setae on metatibia (Tables 5, 7), relative length of LAS and urogomphus compared to HW, larger number of lamellae clypeales (> 27 compared to < 16 in first instar), lamellae clypeales spatulate (first instar), presence of additional setae on mesotibiae (first instar) (Table 4), and primary seta UR7 subequal in length to any of setae UR5, UR6, and UR8 (first instar) (Fig. 14) (see also under R. calidus and R. orbignyi).

Description of larvae of Rhantus anisonychus Crotch, 1873 Source of material. The larvae studied were reared ex ovo from adults collected at the following locality: USA. California, Riverside Co. Elsimore Lake, pond at HWY 74, 15.III.2000, Y. Alarie, leg. Associated larvae from the same locality were also used in this study.


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First-instar larva (n = 7) (Figs 20–24) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Overall predominantly greyish black; head appendages, legs and urogomphus slightly paler (freshly killed larvae). Head. Head capsule (Fig. 20). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale slightly constricted at level of occipital region, with microspinulae covering posterior 2/3 of dorsal surface. Antenna. Microspinulae present over most of dorsal surface, antennomere III with a ventroapical spinula. Maxilla. Palpus with microspinulae present over most of dorsal surface. Labium. Palpus with microspinulae present over most of dorsal surface. Thorax. Legs (Fig. 21–22) Microspinulae present over most of anterior surface; tarsal claws with microspinulae covering basal 1/3 to 1/2 of ventral margin. Abdomen. Urogomphus (Fig. 24). Microspinulae present over most of dorsal surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present; anterior margin of frontoclypeus with 24–25 spiniform to digitiform lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated distally, at about level of seta CO6; meso- and metafemoral seta FE5 elongate and hair-like (Fig. 22); seta TI7 elongate and hair-like (Fig. 22); urogomphus (Fig. 24) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 shorter than any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 3) As first-instar larva except as follows: Head. Maxilla. Microspinulae present along inner margin of stipes. Thorax. Legs. Anteroventral spinulae strongly developed on profemora, tibiae and tarsi; metacoxa with several elongate hair-like secondary setae along dorsal margin (cf. Fig. 27); metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 29). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 5; parietale with 10–13 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 28); urogomphus with secondary setae along both inner and outer margins, outer margin with variable number of hair-like and spine-like secondary setae (cf. Fig. 29). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 9) (Figs 25–29) As second-instar larva except as follows: Colour. Head capsule with an irrorate colour pattern (Fig. 25); thoracic terga with variable number of testaceous maculae; legs dark yellow to pale brown; urogomphus dark yellow to pale brown. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 7 and Figs 26–27; parietale with 11–13 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Rhantus anisonychus groups with those species characterized by the presence of a variable number of elongate hair-like and short spine-like secondary setae along outer margin of urogomphus (Fig. 29) (i.e., R. signatus, R. frontalis (Marsham, 1802), R. capensis (Aubé, 1838), R. binotatus Harris, 1828, R. calileguai, R. socialis (C.O. Waterhouse, 1876), R. phocaenarum). Second- and third-instar larvae of R. LARVAE OF THE GENUS RHANTUS


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anisonychus can readily be distinguished from any species of this group both by a relatively longer maxillary palpus and shorter urogomphus compared to HW (Tables 10, 11). As first-instar larva R. anisonychus can be recognized by the presence of microspinulae on the head appendages and by the distal articulation of the procoxal seta CO7.

Description of larvae of Rhantus binotatus (Harris, 1828) Source of material. The larvae studied were reared ex ovo from adults collected by Y. Alarie at the following localities: Canada. British Columbia. Duteau Creek, 5 km west of Lumby, Hwy 6, 31.V.1992. Ontario, Manitoulin Island. Creek at Hwy 540, 21 km west of Little Current, 28.V. 1998, 10.VI.1998. USA. Colorado. Jefferson Co. Pike National Forest. FR211, off road 77, 6 minutes north of Hwy 24, close to Lake George, 08.V.1998. First-instar larva (n = 2) (Figs 30–34) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Overall predominantly greyish black (freshly killed larvae). Head. Head capsule (Fig. 30). Frontoclypeus extending beyond tips of adnasaliae, with microspinulae over whole dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale slightly constricted at level of occipital region, with microspinulae over whole dorsal surface. Antenna. Microspinulae over most of dorsal surface, A3 with a ventroapical spinula. Maxilla. Palpus with microspinulae over most of dorsal surface. Labium. Palpus with microspinulae over most of dorsal surface. Thorax. Legs (Figs 31–32). Microspinulae present over most of anterior surface; ventral margin of tarsal claws with microspinulae over basal 1/2. Abdomen. Urogomphus (Fig. 34). Microspinulae present over most of dorsal surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present (Fig. 30); anterior margin of frontoclypeus with 19–20 spiniform to digitiform lamellae clypeales (Fig. 30); A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated proximally to articulation of seta CO6; meso- and metafemoral seta FE5 elongate and hair-like (Fig. 32); seta TI7 elongate and hair-like (Fig. 32); urogomphus (Fig. 34) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 shorter than any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 2) As first-instar larva except as follows: Colour. Body yellowish with an irrorate greyish pattern; head appendages piceous, articles infuscate apically; thoracic and abdominal terga I to VI yellowish with a faint greyish pattern and with a narrow blackish stripe mesally; abdominal terga VII and VIII piceous; legs and urogomphi creamy white to pale yellow. Head. Maxilla. Microspinulae lacking along inner margin of stipes. Thorax. Legs. Microspinulae present along anteroventral margin of profemur, tibiae and tarsi; metacoxa with several elongate hair-like secondary setae along dorsal margin (cf. Fig. 37); metafemoral natatory setae along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 39). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 5; parietale with 8–9 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both


ALARIE ET AL.

spine-like and hair-like secondary setae (cf. Fig. 38); urogomphus with secondary setae along both inner and outer margins, outer margin with a variable number of hair-like and spine-like secondary setae (cf. Fig. 39). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 9) (Figs 35–39) As second-instar larva except as follows: Colour. Head appendages predominantly yellowish except A4 and MP3 and apices of A2, A3, MP2 and LP1 piceous. Thorax. Legs (Figs 36–37). Metafemoral natatory setae along distal 1/2 to 3/4 of dorsal margin. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 7 (Figs 36–37); parietale with 7–9 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Second- and third instar of R. binotatus are characterized by the presence of a variable number of elongate hair-like setae and short spine-like setae along outer margin of urogomphus (Fig. 39), a condition found also in R. signatus, R. frontalis, R. capensis, R.anisonychus, R. calileguai, R. socialis and R. phocaenarum. Compared to these species, larvae of R. binotatus can only be confounded to those of R. anisonychus also found in the Nearctic region. Larvae of R. binotatus can readily be distinguished from the latter by the following combination of features: smaller size, slightly longer urogomphus (compared either to HW or LAS), absence of microspinulae along inner margin of stipes (second- and third instar), and the more proximal articulation of the procoxal seta CO7 (first instar).

Description of larvae of Rhantus calidus (Fabricius, 1792) Source of material. The larvae studied were collected in association with adults by Y. Alarie and Y. S. Megna (Universidad de Oriente) at the following locality: Cuba: Santiago de Cuba, Campo Rico II, 03.V.2005. The identification is firm as R. calidus is the only Rhantus species known from Cuba. First-instar larva (n = 1) (Figs 40–44) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Body predominantly piceous black. Head. Head capsule (Fig. 40). Frontoclypeus extending at most at level of tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae over posterior 2/3 of dorsal surface. Antenna. Lacking microspinulae, A3 with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 41–42). Microspinulae present over most of anterior surface; ventral margin of tarsal claws with microspinulae along basal 1/4 to 1/3. Abdomen. Urogomphus (Fig. 44). Microspinulae present over most of dorsal surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe lacking (Fig. 40); anterior margin of frontoclypeus with 16 spiniform lamellae clypeales; A3 lacking additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes with one additional seta on inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; meso- and metafemoral seta FE5 short and spine-like (Fig. 42); seta TI7 short and spine-like (Fig. 42); urogomphus (Fig. 44) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 shorter than any of setae UR5, UR6 or UR8; seta UR5 articulated anterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. LARVAE OF THE GENUS RHANTUS


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Second-instar larva (n = 8) As first-instar larva except as follows: Colour. Head capsule with a few yellowish maculae; legs paler; urogomphus yellowish. Head. Maxilla. Microspinulae present along inner margin of stipes. Thorax. Legs. Anteroventral spinulae weakly developed on profemur, more strongly developed on tibiae and tarsi; metacoxa with several elongate hair-like secondary setae along dorsal margin (cf. Fig. 48); metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Not fractured proximally (cf. Fig. 50). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 5; parietale with 6–11 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with three elongate hook-like secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 49); urogomphus lacking secondary setae (cf. Fig. 50). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 1) (Figs 45–50) As second-instar larva except as follows: Colour. Head capsule (Fig. 45) predominantly yellowish; frontoclypeus with a reticulate dark brown macula mesally; parietale with a dark brown macula mesally and a reticulate dark brown pattern posteriorly; A2, A3, A4, MP2, MP3 and LP2 with a narrow piceous band proximally; thoracic terga piceous with dark yellow maculae; abdominal terga I to VI piceous with a dark yellow maculation pattern; abdominal segments VII and VIII paler; legs dark yellow. Head. Antenna (Fig. 46). A2–A4 secondarily subdivided proximally. Maxilla. MP2 and MP3 secondarily subdivided proximally. Labium. LP2 secondarily subdivided proximally. Thorax. Legs (Figs 47–48). Metafemoral natatory setae along distal ¾ of dorsal margin. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 7 and Figs 47–48; parietale with 9–11 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Third-instar larvae of R. calidus are unique within the genus Rhantus in that A2, A3, A4, MP2, MP3 and LP2 are fractured proximally (best seen under a compound microscope). Compared to the other species studied, larvae of R. calidus are characterized by the absence of secondary setae on urogomphus, a feature also found in larvae of R. antarcticus nahueli (cf. above), R. orbignyi (cf. below), and R. poellerbauerae (Balke et al. 2007). Rhantus calidus can readily be distinguished from any of these species by the following combination of characters: anterior margin of frontoclypeus at most extending to level of tips of adnasaliae, A3 lacking anteroventral additional pores, protarsus and metatibia with a larger number of natatory setae (Tables 5, 7), and much shorter urogomphus (Tables 9–11) (see also under R. antarcticus nahueli and R. orbignyi). The third-instar larva of R. calidus was previously described by Crespo (1987) and Costa et al. (1988).

Description of larvae of Rhantus calileguai Trémouilles, 1984 Source of material. The larvae studied were collected in association with adults by M. Archangesky and M.C Michat at the following locality: Argentina, Jujuy Province, pond at Yala-Termas de Reyes road (about 2000 masl), 25/26.XI.2003. Larvae found in an elongate pond about two meters width, 30 m long and 20 cm deep with some vegetation. It was placed near a shaded stream in a mountainous forested area. No other Rhantus species was collected at that site.


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First-instar larva (n = 6) (Figs 51–55) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Dorsal surface of head dark brown except for a light brown macula enclosing each egg burster; ventral surface light brown except for a narrow, longitudinal, yellowish band centrally; head appendages greyish to light brown, A1 and apices of A3, A4, MP3 and LP2 brown; thoracic and abdominal sclerites light brown, membranous parts yellowish; leg segments yellowish, dorsal surface light brown; urogomphus greyish to pale brown. Head. Head capsule (Fig. 51). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae over whole dorsal surface. Antenna. Microspinulae lacking, A3 with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 52–53). Microspinulae present over most of anterior surface; tarsal claws with microspinulae present over basal 1/4 of ventral margin. Abdomen. Urogomphus (Fig. 55). Microspinulae present over most of dorsal surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present (Fig. 51); anterior margin of frontoclypeus with 19–22 spiniform lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; meso- and metafemoral seta FE5 elongate and hair-like (Fig. 53); seta TI7 elongate and hair-like (Fig. 53); urogomphus (Fig. 55) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 shorter than any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 3) As first-instar larva except as follows: Colour. Dorsal surface of head light brown except for anterior and lateral margins and several small maculae on central portion of FR, posterior to stemmata, anterior to occipital suture and medial to each ocular area yellowish; ventral surface yellowish; head appendages yellowish, apex of LP2 light brown; thoracic and, to a lesser extent abdominal sclerites with a pattern of yellowish maculae on a greyish to light brown background; membranous parts, legs and U yellowish. Head. Maxilla. Microspinulae present along inner margin of stipes. Thorax. Legs. Anteroventral spinulae weakly developed on profemur, more strongly developed on tibiae and tarsi; metacoxa with several elongate hair-like secondary setae along dorsal margin; metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 60). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 5; parietale with 9–12 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 59); urogomphus with secondary setae along both inner and outer margins, outer margin with a variable number of hair-like and spine-like secondary setae (cf. Fig. 60). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 3) (Figs 56–60) As second-instar larva except as follows: Colour. Dorsal surface of head reddish to light brown except for several maculae on central portion of FR, posterior to stemmata, anterior to occipital suture and medial to each ocular area yellowish (Fig. 56); ventral surface dark yellow except for posterolateral areas reddish to light brown bearing several small dark yellow LARVAE OF THE GENUS RHANTUS


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maculae; head appendages yellowish except for apices of MP3 and LP2 light brown and distal 1/2 of MN dark brown; thoracic and abdominal sclerites reddish to light brown, with pattern of dark yellow maculae, sclerites VII and VIII without this pattern; membranous parts testaceous; legs yellow to reddish; urogomphus pale yellowish. Thorax. Legs (Figs 57–58). Metafemoral natatory setae present along distal 1/2 to 3/4 of dorsal margin. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 7 and Figs 57–58; parietale with 12–16 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Second- and third-instar larvae of this Neotropical species are characterized by the presence of a variable number of elongate hair-like and short spine-like secondary setae along the inner margin of urogomphus. This character state is also found in R. anisonychus and R. signatus, both distributed in the Neotropical region. Larvae of R. calileguai can readily be distinguished from those of any of these two species by the following combination of characters: larger size, presence of microspinulae along inner margin of stipes (second- and third instar), anteroventral marginal spinulae weakly developed on profemur (secondand third instar) (Figs 57–58), larger number of natatory setae on mesofemur and metatibia (Tables 5, 7), shorter LAS and longer urogomphus compared to HW (Tables 9–11).

Description of larvae of Rhantus capensis (Aubé, 1838) Source of material. The single third-instar larva studied was collected by S. Persson in association with adults at the following locality: Ethiopia, Arsi province, Bekoji, 10.XI.1988. No other Rhantus species was collected in this temporary pool at 2800 m asl. First- and second instar larvae No specimens available for study. Third-instar larva (n = 1) (Figs 61–65) Measurements and ratios aimed to characterize body shape shown in Table 11. Colour. Body predominantly dark yellow to pale brown; head capsule dark yellow with a dark brown reticulate pattern mesally over frontoclypeus and parietale (Fig. 61); head appendages yellow, most articles infuscate apically; body terga predominantly dark yellow to pale brown; thoracic and abdominal terga I to VI infuscate along posterior margin; legs and urogomphus yellowish. Head. Maxilla. Microspinulae lacking along inner margin of stipes. Thorax. Legs (Figs 62–63). Anteroventral spinulae strongly developed on profemur, tibiae and tarsi; metacoxa with dorsal secondary setae predominantly short; metafemoral natatory setae present along distal 2/ 3 to 3/4 of dorsal margin. Abdomen. Urogomphus (Fig. 65). Fractured proximally. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 7 and Figs 62–63; parietale with 10 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (Fig. 64); urogomphus with secondary setae along both inner and outer margins, outer margin with a variable number of hair-like and spine-like secondary setae (Fig. 65). Remarks. The third-instar larva of the Afrotropical species R. capensis is characterized by the presence of a variable number of elongate hair-like setae and short spine-like setae along outer margin of urogomphus (Fig. 65), which is similar to the condition observed in R. signatus, R. frontalis, R. binotatus, R. anisonychus, R. calileguai, R. socialis and R. phocaenarum. Compared to the other African species studied (i.e., R.


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phocaenarum and R. socialis) the third-instar larva of R. capensis is readily distinguished by the following combination of characters: larger size, microspinulae lacking along inner margin of stipes, anteroventral marginal spinulae weakly developed on profemur, strongly developed on tibiae and tarsi (Figs 62–63), number of natatory setae on metatibia (Table 7), and relative length of LAS and urogomphus (Table 11).

Description of larvae of Rhantus consputus (Sturm, 1834) Source of material. The studied larvae were reared by F. Kögel from eggs laid in captivity by adult specimens collected in riverside pools near Ketsch in Germany. The habitat and biology of the species is described in Kögel (1987). First-instar larva (n = 1) (Figs 66–70) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Body predominantly dark yellow to pale brown. Head. Head capsule (Fig. 66). Frontoclypeus extending beyond level of tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae at most over posterior 1/2 of dorsal surface. Antenna. Lacking microspinulae, A3 with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 67–68). Microspinulae restricted to dorsal margin of coxae and ventral margin of femora; tarsal claws with microspinulae present over basal 1/2 of ventral margin. Abdomen. Urogomphus (Fig. 70). Microspinulae present over most of dorsal surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present; anterior margin of frontoclypeus with 21 spiniform to digitiform lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; meso- and metafemoral seta FE5 elongate and hair-like (Fig. 68); seta TI7 elongate and hair-like (Fig. 68); urogomphus (Fig. 70) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 as long as or longer than any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 1) As first-instar larva except as follows: Colour. Head capsule predominantly brown, with a dark brown macula mesally; head appendages brown, apex of A1, A2, A3, A4, MX2, MX3 and LP2 darker; body terga, legs and urogomphus brownish. Head. Maxilla. Microspinulae present along inner margin of stipes. Thorax. Legs. Anteroventral spinulae well developed on profemur, tibiae and tarsi; metacoxa with several elongate hair-like secondary setae along dorsal margin; metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Not fractured proximally (cf. Fig. 75). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 5; parietale with 11–13 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 74); urogomphus with secondary setae along inner and outer margins, outer margin with elongate hair-like setae only except for one short spine-like seta proximally (cf. Fig. 75). Measurements and ratios aimed to characterize body shape shown in Table 10. LARVAE OF THE GENUS RHANTUS


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Third-instar larva (n = 1) (Figs 71–75) As second-instar larva except as follows: Colour. Paler. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 7 and Figs 72–73; parietale with 12–15 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Compared to the other species studied, larvae of the Palearctic species R. consputus resemble those characterized by the presence of elongate hair-like secondary setae and one short spine-like seta along outer margin of urogomphus (i.e., R. validus, R. simulans Régimbart, 1908, R. wallisi Hatch, 1953, R. suturalis (Macleay, W.S.,1825), R. suturellus (Harris, 1828), R. latitans Sharp, 1882, R. notaticollis (Aubé, 1837), R. exsoletus (Forster, 1771), R. fennicus). Compared to other similar species from the Palearctic region (i.e., R. latitans, R. notaticollis, R. exsoletus, R. fennicus, R. suturellus, R. suturalis), larvae of this species can readily be recognized by the following combination of features: larger size (Tables 9–11), microspinulae present over posterior 1/2 of dorsal surface of parietale and the entire surface of urogomphus (first instar), lamellae clypeales digitiform (first instar), tarsi with one additional seta (Fig. 67) (first instar), stipes lacking additional setae (first instar), procoxal seta CO7 articulated at about level of seta CO6, dorsal secondary setae on metacoxa predominantly short (second and third instar), number of natatory setae on metatibia (second- and third instar) (Tables 5, 7); urogomphus not fractured proximally (Fig. 75), presence of at least two secondary setae on protrochanter and presence of PV secondary setae on tarsi (Tables 7, 8). The third-instar larva of this species was previously described by Galewski (1963) and Kögel (1987).

Description of larvae of Rhantus exsoletus (Forster, 1771) Source of material. The larvae studied were collected by A.N. Nilsson in association with adults at the following localities: Sweden, Ångermanland province, Brattfors, small lake, 27.VI.1998, and Västerbotten province, Vännäs, pond 7.VII.1996. First-instar larva (n = 2) (Figs 76–80) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Body predominantly brown; head capsule yellowish around ocularia; antenna dark brown except A4 predominantly yellow, piceous apically; maxillary and labial palpus dark yellow to pale brown, MP2, MP3 and LP2 darker apically; legs dark yellow to pale brown; urogomphus dark brown. Head. Head capsule (Fig. 76). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae at most over posterior 1/2 of dorsal surface. Antenna. Microspinulae lacking, A3 with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 77–78). Microspinulae restricted to dorsal margin of coxae and ventral margin of femora; tarsal claws with microspinulae over basal 1/2 of ventral margin. Abdomen. Urogomphus (Fig. 80). Microspinulae restricted to basal 1/2 of dorsal surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present (Fig. 76); anterior margin of frontoclypeus with 25 spatulate lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; meso- and metafemoral seta FE5 elongate and hair-like (Fig. 78); seta TI7 elongate and hair-like (Fig. 78); urogomphus (Fig. 80) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 about as


ALARIE ET AL.

long as any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 1) As first-instar larva except as follows: Colour. Frontoclypeus with an irrorate brownish macula mesally; head appendages yellowish, A1, A2, A3, MP1 and LP1 piceous apically; last abdominal tergum paler than rest of body terga; legs and urogomphus dark yellow. Head. Maxilla. Microspinulae lacking along inner margin of stipes. Thorax. Legs. Spinulae well developed along anteroventral margin of profemur, tibiae and tarsi; dorsal secondary setae of metacoxa predominantly short; metafemoral natatory setae covering less than distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 85). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 5; parietale with 10–13 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 84); urogomphus with secondary setae along both inner and outer margins, outer margin with elongate and hair-like setae only, except for one short spine-like seta proximally (cf. Fig. 85). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 1) (Figs 81–85) As second-instar larva except as follows: Colour. Body predominantly dark yellow to pale brown; head capsule (Fig. 81) dark brown, yellowish around ocularia and over occipital region; frontoclypeus and parietale with diffuse reticulate brownish maculae mesodorsally; body terga with a variable number of small yellowish maculae; legs and urogomphus dark yellow to pale brown. Thorax. Legs (Figs 82–83). Metafemoral natatory setae present along less than 1/2 of dorsal margin. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 7 and Figs 82–83; parietale with 9–11 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Rhantus exsoletus is a Palearctic species, which can be grouped with those species characterized by the presence of elongate and hair-like setae and one short spine-like seta along outer margin of urogomphus (Fig. 85) (R. consputus; R. validus, R. simulans, R. wallisi, R. suturellus, R. suturalis, R. latitans, R. notaticollis, R. fennicus). Compared to the other Palearctic species studied (i.e., R. consputus, R. latitans, R. notaticollis, R. fennicus, R. suturellus, R. suturalis), larvae of R. exsoletus are characterized by the following combination of characters: longer antenna compared to length of maxillary palpus, shorter length of LAS compared to HW and longer urogomphus compared to HW (Tables 9–11), presence of microspinulae along inner margin of stipes (second and third instar), number of natatory setae on metatibia (Tables 5, 7) (second and third instar), presence of one additional seta along inner margin of stipes (first instar) and urogomphus fractured proximally (second and third instar) (Fig. 85), presence of at least two secondary setae on protrochanter and presence of PV secondary setae on tarsi (Tables 7, 8). Larvae of this species were previously described by Meinert (1901), Bertrand (1928) and Galewski (1963).



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Description of larvae of Rhantus fennicus Huldén, 1982 Source of material. The larvae studied were collected by A.N. Nilsson in association with adults at the following locality: Sweden, Västerbotten province, Märdsele, river fen 21.VI.1986. First-instar larva (n = 1) (Figs 86–90) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Body predominantly pale brown; head capsule yellowish, pale brown mesally; head appendages, legs and urogomphus testaceous. Head. Head capsule (Fig. 86). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae covering basal 1/3 of dorsal surface. Antenna. Microspinulae lacking, antennomere III with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 87–88). Microspinulae reduced, present over dorsal margin of coxae and ventral margin of femora; tarsal claws with microspinulae over basal 1/3 to 1/2 of ventral margin. Abdomen. Urogomphus (Fig. 90). Microspinulae present over most of dorsal surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present (Fig. 86); anterior margin of frontoclypeus with 24 spatulate lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated proximally to articulation of seta CO6; meso- and metafemoral seta FE5 elongate and hair-like (Fig. 88); seta TI7 elongate and hair-like (Fig. 88); urogomphus (Fig. 90) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 about as long as any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 1) As first-instar larva except as follows: Head. Maxilla. Microspinulae lacking along inner margin of stipes. Thorax. Legs. Anteroventral spinulae well developed on profemur, tibiae and tarsi; metacoxa with elongate hair-like secondary setae along dorsal margin; metafemoral natatory setae along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 95). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 5; parietale with 8–11 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 94); urogomphus with elongate and hair-like secondary setae only, except for one short spine-like secondary seta proximally on outer margin (cf. Fig. 95). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 1) (Figs 91–95) As second-instar larva except as follows: Colour. Head capsule (Fig. 91) with an irrorate colour pattern; thoracic terga with variable number of testaceous maculae; legs and urogomphus dark yellow to pale brown. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 7 and Figs 92–93; parietale with 8–9 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11.


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Remarks. Rhantus fennicus is a Palearctic species, which belongs to the group of species characterized by the presence of elongate and hair-like natatory setae and one shorter spine-like seta along the outer margin of urogomphus (Fig. 95) (R. consputus, R. validus, R. simulans, R. wallisi, R. suturalis, R. suturellus, R. latitans, R. notaticollis, R. exsoletus). Compared to the other Palearctic species studied (i.e., R. consputus, R. latitans, R. notaticollis, R.exsoletus, R. suturellus, R. suturalis), larvae of R. fennicus can be recognized by the following combination of characters: shorter maxillary palpus compared to length of labial palpus and length of urogomphus compared to HW (Tables 9–11), microspinulae lacking along inner margin of stipes, number of natatory setae on metatibia (second and third instar) (Tables 5, 7), procoxal seta CO7 articulated proximally, anterior to seta CO6 (first instar), presence of at least 2 ventral additional setae on tarsi (first instar) (Figs 87–88) (Table 4), and urogomphus fractured proximally (second and third instar) (Fig. 95), presence of at least two secondary setae on protrochanter and presence of PV secondary setae on tarsi (Tables 7, 8). Larvae of this species were previously described by Nilsson (1987).

Description of larvae of Rhantus frontalis (Marsham, 1802) Source of material. The larvae studied were collected in association with adults by A.N. Nilsson at the following locality: Sweden, Närke province, Lake Kvismaren, 1.VI.1982. First-instar larva No specimens available for study. Second-instar larva (n = 1) Measurements and ratios aimed to characterize body shape shown in Table 10. Colour. Body predominantly brown; head capsule with few yellowish maculae. Head. Maxilla. Microspinulae present along inner margin of stipes. Thorax. Legs. Anteroventral spinulae strongly developed on profemur, tibiae and tarsi; metacoxa with short secondary setae along dorsal margin; metafemoral natatory setae along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 100). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 5; parietale with 9–11 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 99); urogomphus with secondary setae along both inner and outer margins, outer margin with a variable number of hair-like and spine-like secondary setae (cf. Fig. 100). Third-instar larva (n = 1) (Figs 96–100) As second-instar larva except as follows: Colour. Head capsule with an irrorate colour pattern (Fig. 96). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 7 and 97–98; parietale with 10 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Rhantus frontalis groups with those species characterized by the presence of a variable number of both elongate hair-like and short spine-like secondary setae along the outer margin of urogomphus (i.e., R. signatus, R anisonychus, R. capensis, R. binotatus, R. calileguai, R. socialis, R. phocaenarum). Among these, R. frontalis is the only species found in the Palearctic region.



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Description of larvae of Rhantus grapii (Gyllenhal, 1808) Source of material. The larvae studied were collected by A.N. Nilsson in association with adults at the following locality: Sweden, Gotland province, Rute and Storugns, smaller wetlands, 2.VII.1996. First-instar larva (n = 1) (Figs 101–106) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Body predominantly creamy white to pale yellow. Head. Head capsule (Fig. 101). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae diverging outward; occipital carina lightly impressed, almost lacking; parietale not constricted at level of occipital region, with microspinulae at most over posterior 1/2 of dorsal surface. Antenna. Microspinulae present over most of dorsal surface, A3 lacking a ventroapical spinula. Maxilla (Fig. 102). Palpus with microspinulae over most of dorsal surface. Labium. Palpus with microspinulae over most of dorsal surface. Thorax. Legs (Figs 103–104). Microspinulae present over most of anterior surface; tarsal claws with microspinulae over basal 1/2 of ventral margin. Abdomen. Urogomphus (Fig.106). Microspinulae present over most of dorsal surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present (Fig. 101); anterior margin of frontoclypeus with 28 spine-like lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 slightly longer than galea (Fig. 102); primary seta MX5 longer than palpifer and galea (Fig. 102); stipes lacking additional setae along inner margin (Fig. 102); anterodorsal primary setae of prementum elongate; procoxal seta CO7 articulated proximally to articulation of seta CO6; meso- and metafemoral seta FE5 elongate and hair-like (Fig. 104); seta TI7 elongate and hair-like (Fig. 104); urogomphus (Fig. 106) with one additional seta; primary seta UR2 longer than seta UR3; primary seta UR4 about as long as any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 2) As first-instar larva except as follows: Colour. Body predominantly brownish; head appendages paler; tergum of abdominal segments VII and VIII slightly paler than rest of body; legs dark brown except distal 1/2 of procoxa creamy white; urogomphus pale brown. Head. Maxilla. Microspinulae lacking along inner margin of stipes. Thorax. Legs. Anteroventral spinulae weakly developed or lacking; dorsal setae of metacoxa predominantly elongate; metafemoral natatory setae covering distal 2/3 of dorsal margin. Abdomen. Urogomphus. Not fractured proximally (cf. Fig. 111). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 5; parietale with 3–6 temporal spine-like setae, most anterior ones articulated at about level of occipital region; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 110); urogomphus with secondary setae along both inner and outer margins, outer margin with elongate and hair-like setae only, lacking short spine-like setae (cf. Fig. 111). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 2) (Figs 107–111) As second-instar larva except as follows: Colour. Tibiae and tarsi yellowish; last abdominal segment pale brown; urogomphus either yellow or brown. Thorax. Legs (Figs 108–109). Metafemoral natatory setae present along distal 3/4 of dorsal margin.


ALARIE ET AL.

Chaetotaxy. Number and position of secondary setae on legs are shown in Table 7 and Figs 108–109; parietale with 6–7 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Larvae of Rhantus grapii are characterized by several unique features within Rhantus: occipital carina lightly impressed (first instar) (Fig. 101), parietale not constricted at level of occipital region (first instar) (Fig. 101), adnasaliae diverging outwards (Fig. 101), A3 lacking a ventroapical spinula (first instar), primary setae MX5 and MX7 elongate, longer than galea (first instar) (Fig. 102), femora with at least one additional seta along dorsal margin (first instar) (Fig. 103), primary seta UR2 longer than seta UR3 (first instar) (Fig. 106), most anterior temporal spine-like setae articulated at level of occipital region (second- and third instar) (Fig. 107), galea elongate (Fig. 102) (cf. ratio GA/MP1, Tables 9–11), and a reduced number of natatory setae on tibiae (second and third instar) (Fig. 109) (Tables 5, 7). All larval instars of this species were previously described by Bertrand (1928) and Galewski (1963).

Description of larvae of Rhantus latitans Sharp, 1882 Source of material. The single third-instar larva studied was collected by M. Hess in association with adults at the following locality: Germany, Bavaria, Deggendorf, 16.VIII.1993. First- and second-instar larvae No specimens available for study. Third-instar larva (n = 1) (Figs 112–116) Measurements and ratios aimed to characterize body shape shown in Table 11. Colour. Body predominantly dark yellow to pale brown; head capsule (Fig. 112) dark yellow with a dark brown reticulate pattern mesally over frontoclypeus and parietale; head appendages yellow, A1, A2, A3, MP1, MP2, MP3, LP1 and LP2 infuscate apically; body terga predominantly dark yellow to pale brown; thoracic and abdominal terga I to VI infuscate mesally, segments VII and VIII brown; legs yellowish; urogomphus yellow proximally, brownish distally. Head. Maxilla. Microspinulae lacking along inner margin of stipes. Thorax. Legs (Figs 113–114). Anteroventral spinulae strongly developed on profemur, tibiae and tarsi; metacoxa with dorsal secondary setae predominantly short; metafemoral natatory setae present along distal 1/ 3 of dorsal margin. Abdomen. Urogomphus (Fig. 116). Not fractured proximally. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 8 and Figs 113–114; parietale with 10 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (Fig. 115); urogomphus with secondary setae along both inner and outer margins, outer margin with elongate hair-like setae only, except for one short spine-like seta proximally (Fig. 116). Remarks. Rhantus latitans is a Palearctic species, which belongs to the group of species characterized by the presence of elongate and hair-like natatory setae and one short spine-like seta along outer margin of urogomphus (Fig. 116) (R. consputus; R. validus, R. simulans, R. wallisi, R. suturellus, R. suturalis, R. fennicus, R. notaticollis, R.exsoletus). Compared to other similar Palearctic species (i.e., R. consputus, R. fennicus, R. notaticollis, R. exsoletus, R. suturellus, R. suturalis), third-instar larvae of R. latitans are readily recognized by the following combination of characters: absence of microspinulae along inner margin of stipes, dorsal secondary setae of metacoxae predominantly short, longer LAS and shorter urogomphus



37

compared to HW (Table 11), and urogomphus not fractured proximally (Fig. 116); presence of at least two secondary setae on protrochanter and presence of PV secondary setae on tarsi (Tables 7, 8). Larvae of this species were described previously by Galewski (1963).

Description of larvae of Rhantus notaticollis (Aubé, 1837) Source of material. The larvae studied were collected by S. Kholin in association with adults at the following locality: Russia, Sakhalin island, Kostromskoye village, temporary pond, 24.VI and 8.IX.1993. First-instar larva (n = 1) (Figs 117–121) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Body predominantly dark brown. Head. Head capsule (Fig. 117). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae covering whole dorsal surface. Antenna. Microspinulae lacking, antennomere III with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 118–119). Microspinulae present over most of anterior surface; tarsal claws with microspinulae over basal 1/2 of ventral margin. Abdomen. Urogomphus (Fig. 121). Microspinulae present over most of dorsal surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present (Fig. 117); anterior margin of frontoclypeus with 20 digitiform lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; meso- and metafemoral seta FE5 elongate and hair-like (Fig. 119); seta TI7 elongate and hair-like (Fig. 119); urogomphus (Fig. 121) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 about as long as any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 1) As first-instar larva except as follows: Head. Maxilla. Microspinulae present along inner margin of stipes. Thorax. Legs. Anteroventral spinulae well developed on profemur, tibiae and tarsi; metacoxa with predominantly short secondary setae along dorsal margin; metafemoral natatory setae along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 126). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 5; parietale with 9–10 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 125); urogomphus with secondary setae along both inner and outer margins, outer margin with elongate and hair-like setae only, except for one short spine-like seta proximally (cf. Fig. 126). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n =2) (Figs 122–126) As second-instar larva except as follows: Colour. Antenna and urogomphus paler. Thorax. Legs (Figs 123–124). Metafemoral natatory setae present along distal 3/4 of dorsal margin.


ALARIE ET AL.

Chaetotaxy. Number and position of secondary setae on legs are shown in Table 8 and Figs 123–124; parietale with 9 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Rhantus notaticollis is a Palearctic species, which belongs to the group of species characterized by the presence of elongate and hair-like natatory setae and one short spine-like seta along outer margin of urogomphus (Fig. 126) (R. consputus; R. validus, R. simulans, R. wallisi, R. suturellus, R. suturalis, R. fennicus, R. latitans, R.exsoletus). Compared to other similar Palearctic species (i.e., R. consputus, R. fennicus, R.latitans, R. exsoletus, R. suturellus, R. suturalis), larvae of R. notaticollis can be distinguished by the following combination of characters: absence of microspinulae along inner margin of stipes, dorsal secondary setae on metacoxa predominantly elongate (best seen in third instar), number of natatory setae on metatibia (second and third instar) (Tables 5, 8), shorter LAS and urogomphus compared to HW (Tables 9– 11), presence of microspinulae over most of dorsal surface of frontoclypeus and urogomphus (first instar), presence of at least two secondary setae on protrochanter and presence of PV secondary setae on tarsi (Tables 7, 8). All instars of R. notaticollis were previously described by Galewski (1963). TABLE 8. Number of secondary setae1 on the legs of instar III of selected species of Rhantus Dejean (acronyms as in Table 1). A = anterior, AD = anterodorsal, AV = anteroventral, CO = coxa, D = dorsal, Di = distal, FE = femur, NS = natatory setae, PD = posterodorsal, PV = posteroventral, Pr = proximal, TA = tarsus, TI = tibia, TR = trochanter, V = ventral, n = number of specimens studied, Total = total number of secondary setae on segment. Segment ProCO

ProTR

ProFE

ProTI

ProTA

MesoCO

MesoTR

MesoFE

Sensillar series D(NS) A V Total Pr Di Total NS (PD) AD AV PD PV Total NS (PD) AD AV PD PV Total NS (PD) AD AV PD PV Total D(NS) A V Total Pr Di Total NS (PD) AD AV PD PV Total

MON3

LAT (n = 1) 13 7–9 4 24–26 3–5 0 3–5 27–28 8–11 23–27 0 9 68–74 27–28 4 5–8 0 3–5 41–43 20–24 2 4–6 0 3–4 31–34 11–12 8–10 4–5 23–27 3 0 3 22–24 15 17–19 0 13–14 69–70

2

(n = 1) 23–25 18 1 42–43 6–7 4 10–11 20–21 34–36 32–36 10 24–26 123–126 23–25 19–22 9–11 1–5 11–12 64–74 15–17 10–14 11–14 4–5 9–11 52–58 25–26 22 0–1 48 10 3 13 20–21 32–43 26–30 1–10 33–34 123–127


NOT (n = 2) 13 8 2–4 25–23 2–3 1 3–4 30–32 10–13 18–21 0 9–11 72 25–26 2–3 5–6 0 4–5 37–39 21 2–3 5 0 3 31 13–16 8–10 3–4 24–30 3–5 0–1 3–6 24–30 11–15 19–21 0 12–17 72–77

PHO

ORB (n = 1) 11 14 1 26 0 0 0 38–41 10–11 7 0 9 65–67 28–30 1 4 0 2 35–37 18 0 4 0 0 22 8–13 11–13 3–4 23–29 2 0 2 36 9–10 13–15 0 10–13 70–72

2

(n = 2) 14–17 9 4–5 27–31 3–5 0 3–5 29–36 6–11 21–24 0 9–10 69–77 25–28 3–4 6–7 0 3–4 38–42 20–21 2 5–7 0 0 28–29 15 12 5–6 32–33 4–6 0 4–6 24–36 16 13–14 0 11–12 66–76

POE3

SIG 2

(n = 1) 27 15–16 0 42–43 5 1–3 6–8 31 28 24–27 1 14–15 99–101 29–30 12–14 7–11 1 8 59–62 19–20 8 11 0 9 47–48 30 21 0 51 7 1–2 8–9 24–27 20–27 14–19 0–1 15–19 73–93

(n = 3) 7–14 6–9 2–4 16–26 2–3 0 2–3 23–25 8–11 11–13 0 8–11 52–57 22–24 2–4 3–5 0 3–5 31–36 16–19 1–2 4–5 0 0 21–26 7–12 6–9 3–6 16–26 1–4 0 1–4 20–24 9–12 12–14 0 11–13 55–60

SIM (n = 2) 13–16 7–9 4 26–27 1 0 1 30–41 8–11 15–17 0 8–11 63–78 29–32 3 4–6 0 3–4 42 17–23 2 3–5 0 0 22–30 12–15 10–12 5 27–31 1–2 0 1–2 29–35 9 14–15 0 10–13 63–71

SOC (n = 3) 14–18 10–13 4–6 30–35 2 0 2 33–38 10–16 11–13 0 9–11 65–74 26–30 2–4 4–6 0 2 36–41 20–23 2 5 0 0 27–30 11–13 8–13 7–8 28–31 3–5 0–1 3–6 32–39 12–22 10–15 0 11–14 65–76

SUT (n = 3) 13–15 6–9 3–6 23–28 2–3 0 2–3 25–28 11–14 14–23 0 10–13 68–72 24–28 3–4 6–7 0 3–5 37–43 19–21 2 4–6 0 2–3 27–35 12–15 8–9 4–6 27–28 3–5 0 3–5 19–27 12–14 19–20 0 13–14 65–73

VAL

WAL 2

(n = 1) (n = 3) 21–23 12–17 19–21 8–10 4–7 5–7 47–48 27–31 6–7 2–4 0–1 0 7 2–4 29–31 31–36 16–19 13–15 20–21 15–25 0 0 11–13 9–11 80 68–85 24–25 25–29 4–5 3–4 5–6 5–6 0 0 8 3–5 41–43 39–42 19–22 23–25 4 2 5 5–6 0 0 5–6 4 34–36 34–37 20–25 11–20 20–22 10–12 7–8 5–6 51–56 26–38 8–10 3–5 0–1 0 9–10 3–5 23–30 29–32 20–22 14–15 18–20 17–20 0 0 12 12–14 73–82 74–80 continued next page


39

TABLE 8. (continued) Segment MesoTI

MesoTA

MetaCO

MetaTR

MetaFE

MetaTI

MetaTA

1

Sensillar

LAT

MON3

NOT

ORB

PHO

POE3

SIG

SIM

SOC

SUT

VAL

WAL

series NS (PD) AD AV PD PV Total NS (PD) AD AV PD PV Total D(NS) A V Total Pr Di Total NS (PD) AD AV PD PV Total NS (PD) AD AV PD PV Total NS (PD) AD AV PD PV Total

(n = 1)2 35 7 11 0 5–6 58–59 26–30 2–3 9–10 0 5 42–48 10–12 9–13 3–4 23–28 4–5 0 4–5 8–9 15–16 14–17 0 13–16 53–55 34–35 9–11 10–11 0 5 59–61 35–37 4 10 0 4–5 54–55

(n = 1) 30 23–24 14–18 5–7 9–13 85–88 28–29 19–20 12–15 2 12–15 74–80 15–19 20–21 0–1 36–40 9–10 3–4 12–14 9–10 40–43 23–26 4–10 26–28 107–112 37–38 25–31 15–17 0–5 13–16 98–99 37–39 20–21 14 0–1 13 85–87

(n = 2) 28–31 4–5 9–12 0 4–5 45–53 27–28 2 7–8 0 4–5 41–42 13–14 9–12 3 25–29 3–6 0–1 3–7 10–11 15–16 13–19 0 9–16 54–55 30–31 7–9 8 0 4 49–52 30–33 2 9–10 0 5 46–50

(n = 1)2 33 1–2 5–7 0 2–3 41–45 23–24 1 6 0 0 31–31 10 17 2–3 29–30 3 1 4 11–12 11 11 0 10 43–44 36 3–4 7–9 0 0–1 46–50 34–35 1 9 0 0 44–45

(n = 2) 30–39 6–9 9–10 0 5–6 50–64 26–33 2–3 9–10 0 2–3 40–48 13 6–10 4–5 23–28 5–8 0–1 5–9 10–17 17–23 12–13 0 12–14 58–60 38–42 8–11 11–13 0 5–8 62–74 36–38 4 10 0 3–5 53–57

(n = 1)2 31–34 16–17 12–14 0–1 6–12 67–76 29–30 16–18 13–14 1–2 9–12 69–75 17–20 24 0 41–44 7–9 1 8–10 18–23 23–30 12–20 0 16 74–84 33–39 16–19 12–14 0–1 9–12 75–80 33–38 14–17 10–11 0 7–10 64–76

(n = 3) 24–29 4–6 7–9 0 2–4 38–46 20–26 2 5–9 0 1–2 29–36 6–10 6–12 3–6 20–24 2–4 0 2–4 6–8 11–14 10–12 0 9–11 39–41 25–31 5–9 7–9 0 3–5 42–50 25–29 2–3 7–10 0 1–2 37–41

(n = 2) 31–36 5 9 0 4 49–54 22–32 2 7–8 0 0 32–41 10–13 6–15 2–5 18–33 2 0 2 10–13 8–12 12–15 0 7 40–44 31–32 5–7 9–10 0 3 49–51 29–36 2–3 8–9 0 0 40–47

(n = 3) 30–34 4–8 5–8 0 3–5 46–52 29–33 3–4 6–8 0 3 42–47 7–9 11–15 4–6 22–28 5–6 0 5–6 16–25 12–16 14–16 0 15 57–71 33–37 6–11 6–9 0 4–5 52–61 33–35 4–5 6–9 0 2–5 45–52

(n = 3) 26–32 4–7 6–9 0 5 42–53 24–30 2 8–10 0 3–6 38–48 11–13 10–11 2–5 24–29 4–5 0 4–5 6–9 16–19 14–19 0 11–15 50–58 24–28 7–11 9–12 0 5–6 47–56 24–35 2–4 8–13 0 4–6 39–58

(n = 1)2 27–29 7–8 9–11 0–2 8 51–56 29 7 8–9 0 7–8 52 18–22 26–28 6–7 51–56 7–8 1–2 9 6 26–27 19–21 0 9–10 60–64 25–29 12 8–11 0–2 9 58–59 33–36 7–8 9–10 0 7–8 58–60

(n = 3) 31–35 7–8 8–9 0 5–6 52–56 29–34 2 7–9 0 4–6 44–49 10–16 11–17 4–5 30–37 4–5 0 4–5 12–15 17–19 15–17 0 7–14 54–62 31–33 7–10 9–10 0 4–6 52–59 33–38 2–4 9–11 0 4–5 49–57

including additional setae, cf. material and methods; 2 both legs of a single specimen included; 3 Balke et al. (2007).

Description of larvae of Rhantus orbignyi Balke, 1992 Source of material. The larvae studied were collected by M. Archangelsky and M.C. Michat at the following localities: Argentina: Magdalena, Buenos Aires Province, 23.VI.2001 (stream with floating vegetation); Buenos Aires City, 25.IX.2000 (big permanent pond with littoral vegetation), 11.VI.2001 (pond about 30 m long with abundant vegetation), IX.2004 (temporary rain pool). They were identified by size and elimination. Two species of Rhantus are historically present in Buenos Aires city and nearby areas: R. signatus, which is very common, and R. orbignyi, which is rare. These larvae are bigger in size than those of R. signatus, and clearly differ in their external appearance. Adults of R. orbignyi are bigger in size than those of R. signatus (Trémouilles 1984). First-instar larva (n = 3) (Figs 127–131) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Dorsal surface of head dark brown except for a light brown macula enclosing each egg burster; head appendages brown except for MN dark brown; thoracic and abdominal tergites, legs and urogomphus brown. Head. Head capsule (Fig. 127). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae covering posterior 1/2 of dorsal surface. Antenna.


ALARIE ET AL.

Microspinulae lacking, antennomere III with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 128–129). Microspinulae reduced to dorsal margin of coxae and ventral margin of femora, tibiae and tarsi; tarsal claws with microspinulae over basal 1/2 of ventral margin. Abdomen. Urogomphus (Fig. 131). Microspinulae present over basal 1/2. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe absent (Fig. 127); anterior margin of frontoclypeus with 15–16 digitiform lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; meso- and metafemoral seta FE5 short and spine-like (Fig. 129); seta TI7 short and spine-like (Fig. 129); urogomphus (Fig. 131) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 about as long as any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 3) As first-instar larva except as follows: Colour. Surface of head dark brown dorsally and ventrally, except for a dorsal yellowish macula posterior to each lateral margin of frontoclypeus; head appendages brown; thoracic and abdominal sclerites brown to dark brown, membranous parts brownish testaceous to light brown; legs brown; urogomphus dark yellow to light brown. Head. Maxilla. Microspinulae present along inner margin of stipes. Thorax. Legs. Ventral marginal spinulae well developed on profemur, tibiae and tarsi; metacoxa with predominantly elongate hair-like secondary setae along dorsal margin; metafemoral natatory setae along distal 3/4 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 136). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 6; parietale with 5–6 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 135); urogomphus lacking secondary setae (cf. Fig. 136). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 3) (Figs 132–136) As second-instar larva except as follows: Colour. Surface of head dark brown to dark ferrugineous dorsally (Fig. 132); head appendages brown except for MN dark brown; thoracic tergites pale black to dark ferrugineous; abdominal tergites I–VI dark brown to pale black, sclerites VII and VIII brown; membranous parts testaceous to brownish; legs brown to dark brown; urogomphus yellow to pale brown, distal portion dark. Thorax. Legs (Figs 133–134). Metafemoral natatory setae present along distal 3/4 of dorsal margin. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 8 and Figs 133–134; parietale with 7 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Larvae of R. orbignyi are likely to be confounded with those of R. calidus and R. antarcticus nahueli (see under R. antarcticus nahueli) owing to the absence of secondary setae on urogomphus. Compared to these species, R. orbignyi can be easily recognized by the following combination of features: size, relative elongation of A4 compared to A3, longer antenna compared to length of maxillary palpus



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(Tables 9–11), presence of microspinulae along inner margin of stipes, number of natatory setae on metatibia (second and third instar) (Tables 6, 8) (see also under R. calidus and R. antarcticus nahueli). The third-instar larva of R. orbignyi was previously described by Crespo (1987). TABLE 9. Measurements and ratios for the instar I of selected species of Rhantus (acronyms as in Table 1); l, length; w, width; ?, missing data. Measure HL (mm) HW (mm) FRL (mm) OCW (mm) HL/HW HW/OCW A/HW A4/A1 A4/A3 MN(l/w) A/MP MP3/MP2 GA/MP1 MP/LP LP2/LP1 L3 (mm) L3/HW LAS (mm) LAS/HW U (mm) U/HW U/LAS

ANI (n = 3) 0.88–1.00 0.87–0.92 0.42–0.45 0.47–0.48 1.01–1.09 1.83–1.96 0.86–0.93 1.41–1.50 1.14–1.17 2.48–2.62 1.34–1.46 1.22–1.31 0.48–0.55 1.19–1.23 1.14–1.22 2.61–2.79 3.00–3.06 0.57–0.70 0.66–0.76 1.26–1.31 1.37–1.47 1.79–2.23

ANT (n = 6) 1.32–1.39 1.34–1.44 0.62–0.67 0.76–0.88 0.94–1.04 1.64–1.76 0.65–0.70 1.72* 1.22–1.31 2.67–2.85 1.41–1.53 1.27–1.35 0.60–0.70 0.94–0.99 1.07–1.15 3.99–4.16 2.89–2.99 0.82–0.84 0.58–0.61 1.54–1.78 1.15–1.29 1.88–2.02

BIN (n = 2) 0.90–0.91 0.86–0.87 0.43–0.44 0.45–0.46 1.04–1.05 1.91–1.93 0.99–1.00 1.49–1.51 1.14–1.15 2.44–2.45 1.50–1.51 1.17–1.19 0.49–0.50 1.19–1.21 0.92–1.00 2.69–2.73 3.12–3.13 0.60–0.62 0.70–0.71 1.34–1.36 1.55–1.56 2.17–2.21

CAL (n = 1) 0.88 1.06 0.44 0.53 0.88 2.02 1.06 1.07 0.83 2.56 1.40 1.05 0.43 1.20 1.04 2.69 2.54 0.97 0.92 0.84 0.80 0.87

CAG (n = 6) 0.87–0.99 0.86–0.89 0.43–0.47 0.42–0.47 1.01–1.11 1.82–2.12 0.82–0.94 1.33–1.73 0.95–1.12 2.38–2.73 1.37–1.55 1.11–1.22 0.47–0.57 1.09–1.25 1.00–1.34 2.62–2.88 3.00–3.29 0.51–0.57 0.59–0.64 1.33–1.62 1.49–1.87 2.33–3.12

CON (n = 1) 1.20 1.09 0.51 ? 1.10 ? 1.13 1.42 0.96 2.65 1.66 1.16 0.48 1.09 1.06 3.16 2.91 0.97 0.89 1.49 1.37 1.53

SOC (n = 3) 0.87–0.91 0.79–0.85 0.41–0.44 0.41–0.44 1.05–1.09 1.90–2.05 0.96–1.01 1.33–1.38 1.02–1.08 2.51–2.69 1.40–1.42 1.18–1.19 0.50–0.55 1.18–1.26 1.02–1.05 2.56–2.61 3.07–3.23 0.52–0.53 0.62–0.66 1.30–1.38 1.56–1.70 2.47–2.62

SUT (n = 2) 1.07–1.14 1.08 0.48–0.51 0.46–0.52 0.99–1.06 2.09–2.36 1.05–1.12 1.66–1.74 1.14–1.19 2.44–2.58 1.56–1.59 1.12–1.25 0.49–0.50 0.99–1.01 0.94–1.03 3.04–3.13 2.83–2.91 0.92–0.94 0.86–0.88 1.34–1.57 1.24–1.47 1.45–1.67

EXS (n = 2) 1.15–1.17 1.03–1.05 0.47–0.50 0.41–0.44 1.09–1.13 2.35–2.55 1.35–1.37 1.53–1.66 1.16–1.22 2.43–2.53 1.66–1.67 1.16–1.18 0.47–0.48 1.07–1.13 1.01–1.04 3.45–3.60 3.35–3.43 0.87–0.88 0.83–0.86 1.82–1.83 1.75–1.77 2.07–2.10

FEN (n = 1) 1.10 1.01 0.50 0.53 1.12 1.92 1.08 1.87 1.24 3.00 1.30 1.16 0.50 1.18 1.18 3.22 3.19 0.91 0.90 1.47 1.45 1.61

GRA (n = 1) 1.09 1.01 0.58 0.56 1.08 1.79 1.00 1.78 1.55 2.84 1.70 1.60 1.28 1.05 0.85 2.89 2.86 1.00 0.99 1.00 0.99 1.00

TABLE 9. Continuation. Measure HL (mm) HW (mm) FRL (mm) OCW (mm) HL/HW HW/OCW A/HW A4/A1 A4/A3 MN(l/w) A/MP MP3/MP2 GA/MP1 MP/LP LP2/LP1 L3 (mm) L3/HW LAS (mm) LAS/HW U (mm) U/HW U/LAS

NOT (n = 1) 0.99 0.95 0.43 0.42 1.14 2.28 1.14 1.59 1.15 2.67 1.58 1.18 0.48 1.01 0.99 2.95 3.11 0.82 0.87 1.42 1.49 1.72

ORB (n = 3) 1.08–1.16 1.02–1.07 0.56 0.51–0.52 1.05–1.10 1.95–2.10 0.86–0.91 1.61–1.80 1.13–1.25 2.58–2.95 1.63–1.70 1.25–1.39 0.53–0.65 1.04–1.08 1.09–1.11 3.13–3.31 3.05–3.11 0.67–0.98 0.66–0.92 1.26–1.44 1.19–1.41 1.34–2.15

PHO (n = 1) 0.99 0.95 0.43 0.55 1.06 1.87 0.95 1.23 0.98 2.55 1.44 1.15 0.49 1.17 1.07 3.17 3.07 0.69 0.67 1.70 1.65 2.46

SIG (n = 5) 0.85–0.92 0.78–0.89 0.38–0.43 0.37–0.43 0.97–1.12 1.86–2.22 0.90–1.01 1.43–1.78 1.10–1.25 2.11–2.55 1.38–1.48 1.27–1.47 0.44–0.59 1.08–1.16 1.00–1.14 2.38–2.64 3.08–3.21 0.56–0.62 0.63–0.78 1.26–1.44 1.48–1.78 2.10–2.53

VAL (n = 2) 1.40 1.26–1.28 0.64–0.66 0.62–0.66 1.09–1.11 1.94–2.03 0.77 1.48–1.49 1.16–1.19 2.77 1.27–1.29 1.33–1.46 0.52–0.56 1.13–1.15 1.18–1.24 3.61–3.75 2.87–2.93 0.78–0.82 0.62–0.64 1.28–1.34 1.00–1.06 1.56–1.72

WAL (n = 2) 1.12–1.13 1.04–1.05 0.49–0.50 0.46–0.49 1.08–1.09 2.16–2.28 1.25–1.28 1.62–1.66 1.08–1.10 2.35–2.40 1.73–1.76 1.10–1.12 0.43 1.00–1.05 0.97–1.04 3.21–3.23 3.06–3.12 0.87–0.90 0.82–0.83 1.54–1.55 1.47–1.50 1.73–1.77

Description of larvae of Rhantus phocaenarum Guignot, 1957 Source of material. The larvae studied were collected in association with adults by L. Hendrich at the following localities. La Réunion, Fundarte, Cilias, 1200 m, 26–30.XII.1998; SE St-Paul, SE Petite France,


ALARIE ET AL.

1800 m, 22–25.XII.1998; NW LaPaline des palmists, Forêt de Bélouve, 1400 m, 3.I.1999. The association is safe as R. phocaenarum is the only species of Rhantus found in La Réunion. First-instar larva (n = 1) (Figs 137–141) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Body uniformly brown; head appendages brown except A1 creamy white; legs and urogomphus brown. Head. Head capsule (Fig. 137). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over most of dorsal surface except along anterior margin; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae over most of dorsal surface. Antenna. Microspinulae lacking, antennomere III with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 138–139). Microspinulae over most of anterior surface; tarsal claws with microspinulae covering basal 2/3 of ventral margin. Abdomen. Urogomphus (Fig. 141). Microspinulae present over most surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present (Fig. 137); anterior margin of frontoclypeus with 23 digitiform to spiniform lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; mesoand metafemoral seta FE5 elongate and hair-like (Fig. 139); seta TI7 elongate and hair-like (Fig. 139); urogomphus (Fig. 141) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 shorter than any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 2) As first-instar larva except as follows: Colour. Paler. Head. Maxilla. Microspinulae lacking along inner margin of stipes. Thorax. Legs. Anteroventral spinulae weakly developed on profemur, well-developed on tibiae and tarsi; metacoxa with predominantly short hair-like secondary setae along dorsal margin; metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 146). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 6; parietale with 10–12 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 145); urogomphus with secondary setae along both inner and outer margins, outer margin with a variable number of hair-like and spine-like secondary setae (cf. Fig. 146). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 2) (Figs 142–146) As second-instar larva except as follows: Colour. Dorsal surface of head capsule with a variable number of yellowish maculae. Thorax. Legs (Figs 143–144). Metafemoral natatory setae present along distal 1/2 of dorsal margin. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 8 and Figs 143–144; parietale with 11–13 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Rhantus phocaenarum belongs to the group of species characterized by the presence of a variable number of elongate hair-like and short spine-like secondary setae along the outer margin of LARVAE OF THE GENUS RHANTUS


43

urogomphus (Fig. 146) (i.e., R. signatus, R. frontalis, R. capensis, R. binotatus, R. calileguai, R. socialis, R. anisonychus). Compared to other African species included in this group (R. capensis and R. socialis) larvae of R. phocaenarum are readily distinguished by the following combination of characters: absence of microspinulae along inner margin of stipes (second and third instar), anteroventral spinulae of profemur reduced (second and third instar) (Fig. 143), number of natatory setae on metatibia (second- and third instar) (Tables 6, 8), relative elongation of LAS and urogomphus with respect to HW (Tables 9–11) and distal articulation of procoxal seta CO7 (first instar). TABLE 10. Measurements and ratios for the instar II of selected species of Rhantus (acronyms as in Table 1); l, length; w, width. Measure

ANI (n = 2)

ANT (n = 6)

BIN (n = 2)

RCAL (n = 2)

CAG (n = 3)

CON (n = 1)

EXS (n = 2)

FEN (n = 1)

HL (mm) HW (mm) FRL (mm) OCW (mm) HL/HW HW/OCW A/HW A4/A1 A4/A3 MN(l/w) A/MP MP3/MP2 GA/MP1 MP/LP LP2/LP1 L3 (mm) L3/HW LAS (mm) LAS/HW U (mm) U/HW U/LAS

1.54–1.57 1.50–1.54 0.68–0.69 0.83–0.85 1.02–1.03 1.82–1.84 0.75–0.76 1.14–1.15 0.92–0.95 2.88–3.00 1.42–1.44 0.95–1.03 0.37–0.39 1.25–1.30 0.98–1.04 4.36–4.41 2.83–2.94 1.30–1.32 0.85–0.87 1.98–2.20 1.28–1.47 1.52–1.69

2.06–2.22 2.14–2.20 0.92–0.98 1.16–1.22 0.96–1.02 1.75–1.88 0.55–0.57 1.11 1.16–1.17 2.42–2.64 1.39–1.42 1.11–1.18 0.56–0.61 0.96–1.02 0.88–0.93 5.86–6.04 2.71–2.77 1.68–1.78 0.76–0.83 2.10–2.20 0.95–0.99 1.19–1.25

1.45–1.52 1.43–1.45 0.66–0.63 0.85–0.94 1.00–1.07 1.54–1.68 0.78–0.79 1.02–1.04 0.87–0.93 2.53–2.68 1.45–1.48 1.02–1.03 0.44–0.49 1.14–1.15 0.91–0.92 4.20–4.22 2.91–2.95 1.20–1.30 0.83–0.91 2.00–2.01 1.38–1.41 1.54–1.67

1.44–1.48 1.60–1.63 0.68 0.79–0.84 0.88–0.92 1.93–2.02 0.80–0.81 0.71–0.73 0.70–0.74 2.88–3.09 1.44–1.48 0.78–0.85 0.34–0.43 1.19–1.21 0.83–0.89 4.29–4.34 2.67–2.68 2.08–2.18 1.30–1.34 0.91–1.05 0.57–0.65 0.44–0.48

1.41–1.55 1.34–1.46 0.62–0.67 0.72–0.84 1.06 1.69–1.86 0.75–0.77 1.06–1.21 0.87–0.98 2.78–3.00 1.43–1.51 0.89–0.98 0.29–0.44 1.17–1.23 0.82–0.92 3.85–4.40 2.87–3.00 1.03–1.29 0.77–0.88 1.95–2.43 1.45–1.67 1.85–2.00

1.73 1.70 0.72 0.90 1.05 1.89 0.94 1.00 0.75 2.60 1.70 0.88 0.49 1.13 0.79 4.65 2.74 1.80 1.06 1.98 1.16 1.10

1.80–1.83 1.63–1.64 0.74–0.75 0.80–0.83 1.10–1.13 1.97–2.05 1.08–1.12 1.23–1.28 1.02–1.07 2.66–2.68 1.62–1.66 0.99–1.06 0.43–0.44 1.07 1.10 5.03–5.11 3.07–3.14 1.75–1.83 1.07–1.12 2.50–2.70 1.54–1.65 1.37–1.54

1.68 1.59 0.73 0.80 1.05 1.99 0.77 1.35 1.06 3.03 1.29 1.02 0.43 1.20 0.94 4.75 2.99 1.83 1.15 1.95 1.23 1.07

FOR* (n = 4) 1.83–2.00 1.86–1.98 0.80–0.82 0.92–1.02 0.97–1.01 1.84–2.05 0.61–0.66 0.90–0.97 0.90–0.97 2.61–2.63 1.29–1.36 0.92–0.98 0.40–0.44 1.34–1.43 0.89–0.96 4.82–5.04 2.55–2.64 1.31–1.43 0.69–0.75 2.05–2.28 1.08–1.16 1.44–1.67

TABLE 10. Continuation. Measure

FRO GRA (n = 1) (n = 2)

NOT ORB (n = 1) (n = 3)

PHO (n = 2)

SIG (n = 4)

SOC (n = 2)

HL (mm) HW (mm) FRL (mm) OCW (mm) HL/HW HW/OCW A/HW A4/A1 A4/A3 MN(l/w) A/MP MP3/MP2 GA/MP1 MP/LP LP2/LP1 L3 (mm) L3/HW LAS (mm) LAS/HW U (mm) U/HW U/LAS

1.57 1.55 0.70 0.88 1.02 1.78 0.83 1.11 0.96 2.63 1.57 0.90 0.38 1.13 0.80 4.82 3.11 1.60 1.03 2.35 1.52 1.47

1.64 1.58 0.70 0.78 1.04 2.03 0.92 1.37 1.14 2.56 1.64 0.97 0.43 0.99 0.86 4.49 2.85 1.63 1.03 2.03 1.29 1.25

1.60–1.64 1.55–1.63 0.70–0.73 0.76–0.85 1.01–1.04 1.91–2.11 0.78–0.81 0.97–1.02 0.84–0.87 2.67–2.79 1.41–1.46 1.02–1.05 0.42–0.43 1.20–1.22 0.83–0.90 4.70–4.72 2.89–3.04 1.08–1.10 0.66–0.71 2.50–2.63 1.54–1.69 2.33–2.39

1.32–1.48 1.25–1.32 0.60–0.65 0.66–0.70 1.06–1.16 1.84–1.91 0.78–0.85 1.13–1.24 0.97–1.20 2.58–2.68 1.43–1.53 1.03–1.10 0.42–0.50 1.10–1.15 0.81–0.96 3.87–4.15 3.07–3.17 1.10–1.26 0.88–0.96 1.73–2.00 1.38–1.60 1.51–1.82

1.40–1.41 1.35–1.41 0.61–0.62 0.69–0.73 1.00–1.03 1.95 0.77–0.79 1.00–1.04 0.90–0.93 2.67–2.82 1.43–1.48 0.98–1.02 0.46–0.48 1.18–1.23 0.83–0.85 3.92–3.97 2.82–2.90 0.89–0.95 0.66–0.67 2.09–2.14 1.52–1.55 2.25–2.35

1.67 1.48 0.79–0.80 0.90–0.93 1.13 1.60–1.64 0.87–0.92 1.27–1.36 1.19–1.27 2.80–2.83 1.64–1.85 1.28–1.41 0.83–0.95 1.00–1.05 0.88–0.91 4.43–4.60 3.00–3.12 2.00–2.03 1.36–1.37 1.56–1.60 1.06–1.09 0.78–0.79

1.61–1.68 1.59–1.64 0.76–0.80 0.96–1.12 0.98–1.04 1.47–1.66 0.69–0.71 1.28–1.31 1.07–1.12 2.46–2.71 1.58–1.61 1.13–1.16 0.55–0.59 1.08–1.09 0.95 4.59–4.66 2.81–2.93 1.56–1.59 0.96–0.99 1.36–1.73 0.84–1.09 0.87–1.09

SUT (n = 2) 1.76–1.83

VAL (n = 1) 2.28

WAL (n = 2) 1.80–1.81

1.73–1.75 0.76–0.78 0.80–0.90 1.01–1.06 1.94–2.16 0.90–0.94 1.18–1.33 0.91–1.02 2.41–2.70 1.57–1.58 0.97–1.00 0.38–0.39 1.02–1.03 0.82–0.83 4.65–4.80 2.65–2.78 1.70 0.97–0.99 2.10–2.33 1.20–1.35 1.24–1.37

2.06 1.02 1.10 1.11 1.87 0.64 0.97 0.91 2.81–3.00 1.32–1.35 1.05–1.13 0.41–0.45 1.24–1.30 1.06 5.98–6.06 2.90–2.94 1.70 0.83 1.96–2.04 0.95–0.99 1.15–1.20

1.68–1.69 0.73–0.75 0.85–0.88 1.07–1.08 1.93–1.97 0.93–0.98 1.20–1.22 0.89–0.95 2.53–2.73 1.65–1.66 0.88–0.89 0.40–0.43 0.98–1.03 0.81–0.82 4.69–4.74 2.80–2.81 1.70 1.01–1.02 1.98–2.13 1.17–1.27 1.16–1.25

* from Alarie & Wang (2004)


ALARIE ET AL.

TABLE 11. Measurements and ratios for the instar III larvae of selected species of Rhantus (acronyms as in Table 1); l, length; w, width. Measure HL (mm) HW (mm) FRL (mm) OCW (mm) HL/HW HW/OCW A/HW A4/A1 A4/A3 MN(l/w) A/MP MP3/MP2 GA/MP1 MP/LP LP2/LP1 L3 (mm) L3/HW LAS (mm) LAS/HW U (mm) U/HW U/LAS

ANI (n = 3) 2.63–2.66 2.35–2.58 1.00–1.05 1.38–1.50 1.02–1.12 1.71–1.90 0.64–0.66 0.82–0.86 0.82–0.84 2.92–3.11 1.38–1.43 0.79–0.85 0.37–0.38 1.26–1.28 0.69–0.76 6.66–7.28 2.69–2.87 2.18–2.35 0.85–0.93 2.58–3.10 1.10–1.22 1.18–1.31

ANT (n = 6) 3.19–3.36 3.06–3.16 1.27–1.38 1.98–2.00 1.04–1.06 1.53–1.60 0.50–0.51 0.81–0.85 1.04–1.07 2.86–2.93 1.37–1.39 0.98–1.02 0.52–0.54 0.99–1.06 0.84–0.87 8.71–8.82 2.79–2.87 3.04–3.12 0.96–1.02 2.50–2.72 0.84–0.86 0.83–0.89

BIN (n = 3) 2.19–2.25 2.08–2.20 0.89–1.00 1.35–1.43 1.01–1.06 1.52–1.57 0.67–0.72 0.74–0.89 0.85–0.89 2.85–3.01 1.42–1.45 0.78–0.85 0.37–0.41 1.16–1.20 0.70–0.76 6.09–6.37 2.90–2.94 1.80–2.00 0.82–0.92 2.80–3.05 1.35–1.40 1.49–1.65

CAG (n = 3) 2.50–2.53 2.38–2.46 1.02–1.05 1.41–1.49 1.03–1.05 1.60–1.72 0.62–0.64 0.73–0.83 0.73–0.80 2.97–3.22 1.38–1.47 0.74–0.86 0.35–0.41 1.13–1.19 0.70–0.75 6.77–6.90 2.79–2.86 1.98–2.08 0.83–0.86 3.29–3.70 1.38–1.51 1.61–1.82

CAL (n = 3) 2.30–2.43 2.35–2.53 0.98–1.08 1.35–1.45 0.96–0.98 1.74–1.78 0.71–0.85 0.53–0.59 0.63–0.67 3.02–3.04 1.46–1.48 0.69–0.73 0.37–0.40 1.12–1.17 0.72–0.81 6.54–7.10 2.73–2.81 3.55–3.68 1.46–1.51 0.85–1.15 0.35–0.46 0.24–0.31

CAP (n = 1) 2.54 2.48 0.94 1.48 1.03 1.68 0.68 0.88 0.86 2.94 1.46 0.80 0.38 1.19 0.66 6.86 2.77 2.18 0.88 3.05 1.23 1.40

CON (n = 1) 2.88 2.63 1.10 1.48 1.10 1.78 0.78 0.83 0.79 2.99 1.62 0.78 0.45 1.14 0.68 7.32 2.79 3.00 1.14 2.98 1.13 0.99

EXS (n = 2) 2.53–2.63 2.23–2.30 0.95–1.00 1.58–1.63 1.13–1.14 1.82–1.88 0.87–0.93 0.97–0.98 0.89–0.92 2.89–3.01 1.63–1.69 0.86–0.88 0.50 1.05–1.06 0.70–0.74 6.45–6.50 2.83–2.85 2.78–2.80 1.22–1.25 3.03–3.13 1.32–1.41 1.08–1.13

FEN (n = 2) 2.49–2.50 2.33–2.40 1.03–1.04 1.30 1.04–1.08 1.79–1.85 0.67–0.69 1.07 0.90–0.91 3.16–3.35 1.24–1.25 0.77–0.83 0.33–0.40 1.18–1.23 0.79–0.85 6.69–6.71 2.79–2.88 2.58–2.65 1.07–1.14 2.25–2.33 0.97–0.98 0.85–0.90

TABLE 11. Continuation. Measure HL (mm) HW (mm) FRL (mm) OCW (mm) HL/HW HW/OCW A/HW A4/A1 A4/A3 MN(l/w) A/MP MP3/MP2 GA/MP1 MP/LP LP2/LP1 L3 (mm) L3/HW LAS (mm) LAS/HW U (mm) U/HW U/LAS

FOR1 (n = 3) 2.85–2.88 2.80–3.03 1.13–1.20 1.56–1.70 0.94–1.03 1.74–1.92 0.53–0.56 0.65–0.71 0.79–0.84 2.73–2.98 1.27–1.32 0.79–0.83 0.39–0.41 1.39–1.43 0.71–0.76 7.11–7.33 2.36–2.53 1.98–2.20 0.67–0.75 2.75–3.00 0.91–1.06 1.25–1.52

FRO (n = 1) 2.55 2.43 1.05 1.50 1.05 1.62 0.72 0.98 0.93 2.92 1.52 0.92 0.39 ––– ––– 7.21 2.97 2.80 1.16 3.60 1.49 1.29

GRA (n = 2) 2.40–2.45 1.85–1.95 1.03–1.10 1.28–1.35 1.26–1.30 1.44–1.45 0.77–0.82 0.95–1.08 1.08–1.20 3.14–3.23 1.65–1.74 1.08–1.21 0.78–0.81 1.03–1.06 0.74–0.77 6.21–6.47 3.32–3.36 2.83–2.88 1.47–1.53 1.85–1.98 0.95–1.07 0.64–0.70

LAT (n = 1) 2.68 2.35 0.95 1.33 1.14 1.77 0.81 0.87 0.86 2.95 1.59 0.90 0.42 1.09 0.77 6.74 2.87 3.15 1.34 2.50 1.06 0.79

MON2 (n = 1) 3.75 4.28 1.38 2.03 0.88 2.11 0.57 0.57 0.65 3.10 1.24 0.77 0.36 1.39 0.67 10.01 2.34 2.65 0.62 2.825 0.66 1.07

NOT (n = 2) 2.65–2.73 2.48–2.50 1.03–1.05 1.63–1.68 1.07–1.09 1.62–1.70 0.72–0.73 0.91–0.98 0.87–0.88 2.80–2.86 1.58–1.61 0.87 0.39–0.44 1.00–1.02 0.70–0.76 6.94–6.96 2.77–2.81 2.85–2.93 1.15–1.17 2.73–3.03 1.10–1.21 0.96–1.03

ORB (n = 1) 2.90 2.77 1.22 1.97 1.05 1.41 0.56 0.90 1.00 2.70–2.73 1.60 0.98 0.43 1.09 0.82–0.84 7.61 2.75 3.20 1.16 2.13–2.17 0.77–0.78 0.67–0.68

PHO (n = 2) 2.40–2.58 2.25–2.50 0.98–1.03 1.23–1.35 1.03–1.07 1.61–1.84 0.63–0.71 0.72–0.77 0.74–0.77 2.89 1.41–1.53 0.83–0.87 0.39 1.14–1.20 0.79 6.26–6.78 2.71–2.78 1.48–1.55 0.62–0.66 3.00–3.45 1.33–1.38 2.03–2.23

POE1 (n = 2) 3.10–3.35 3.48–3.55 1.10–1.15 1.58–1.60 0.89–0.94 2.17–2.25 0.56 0.49–0.52 0.68–0.73 3.41–3.43 1.30–1.35 0.83–0.84 0.40–0.43 1.26–1.30 0.62–0.63 7.96–8.05 2.24–2.32 2.28–2.30 0.64–0.66 2.35–2.40 0.66–0.69 1.03–1.04

TABLE 11. Continuation. Measure

SIG (n = 3)

SIM (n = 2)

SOC (n = 3)

SUT (n = 3)

VAL (n = 1)

WAL (n = 3)

HL (mm) HW (mm) FRL (mm) OCW (mm) HL/HW HW/OCW A/HW A4/A1 A4/A3 MN(l/w) A/MP

2.14–2.21 2.04–2.30 0.85–0.94 1.22–1.29 0.96–1.05 1.58–1.67 0.62–0.74 0.87–1.00 0.81–0.92 2.42–2.86 1.43–1.53

2.40–2.63 2.33–2.55 0.95–1.13 1.43 1.03 1.63 0.66–0.70 0.76–0.77 0.79–0.88 2.86–3.01 1.60–1.64

2.10–2.25 2.03–2.08 0.88–0.93 1.10–1.15 1.04–1.11 1.80–1.84 0.64–0.66 0.74–0.78 0.77–0.78 2.87–2.97 1.43–1.48

2.43–2.65 2.35–2.50 0.95–1.05 1.20–1.35 1.08–1.11 1.84–2.01 0.73–0.83 1.03–1.05 0.89–0.98 2.86–3.00 1.44–1.53

3.54 3.40 1.44 1.90 1.04 1.79 0.52 0.73–0.87 0.76 2.77–2.84 1.24–1.25

2.56–2.65 2.38–2.45 0.99–1.05 1.25–1.30 1.08 1.89–1.90 0.82–0.87 0.88–0.98 0.88–0.94 2.69–2.86 1.57–1.62

continued next page



45

TABLE 11. Continue. Measure MP3/MP2 GA/MP1 MP/LP LP2/LP1 L3 (mm) L3/HW LAS (mm) LAS/HW U (mm) U/HW U/LAS 1

SIG (n = 3) 0.90–0.94 0.41–0.43 1.11–1.18 0.75–0.77 5.42–5.97 2.58–2.89 1.86–1.94 0.84–0.95 2.52–2.94 1.23–1.44 1.30–1.58

SIM (n = 2) 0.77–0.79 0.41–0.45 1.05–1.15 0.71–0.73 6.05–6.42 2.52–2.60 2.15–2.33 0.91–0.93 2.28 0.89–0.98 0.98–1.06

SOC (n = 3) 0.79–0.88 0.32–0.44 1.20–1.25 0.69–0.75 5.29–5.44 2.61–2.65 1.33–1.43 0.65–0.70 2.65–2.70 1.30–1.32 1.88–2.02

SUT (n = 3) 0.83–0.94 0.33–0.44 1.06–1.15 0.69–0.76 6.38–6.71 2.68–2.75 2.33–2.90 0.99–1.20 2.25–3.03 0.96–1.25 0.90–1.04

VAL (n = 1) 0.91–0.95 0.35–0.36 1.17–1.20 0.79 8.84–8.88 2.60–2.61 2.80 0.82 2.36–2.54 0.69–0.75 0.84–0.91

WAL (n = 3) 0.77–0.79 0.35–0.39 1.05–1.15 0.60–0.66 6.61–6.70 2.70–2.79 2.58–2.70 1.05–1.11 2.35–2.58 0.99–1.05 0.89–1.00

from Alarie & Wang (2004); 2 Balke et al. (2007)

Description of larvae of Rhantus signatus (Fabricius, 1775) Source of material. The larvae studied were reared ex ovo in the laboratory from adults collected by M. Archangelsky and M.C. Michat at the following locality: Argentina, Buenos Aires City, IX.2000. First-instar larva (n = 5) (Figs 147–151) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Dorsal surface of head light brown except for anterolateral margins of frontoclypeus and several maculae on central portion of frontoclypeus yellowish; head appendages yellowish to light brown, apex of A3 light brown; thoracic and abdominal sclerites light brown; legs and urogomphus yellowish to light brown. Head. Head capsule (Fig. 147). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae over posterior 1/2 of dorsal surface. Antenna. Microspinulae lacking, antennomere III with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 148–149). Microspinulae present on dorsal margin of coxae and ventral margin of femora, tibiae and tarsi; tarsal claws with microspinulae covering basal 1/2 of ventral margin. Abdomen. Urogomphus (Fig. 151). Microspinulae present over basal 1/2. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present (Fig. 147); anterior margin of frontoclypeus with 16–23 digitiform to spiniform lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; mesoand metafemoral seta FE5 elongate and hair-like (Fig. 149); seta TI7 elongate and hair-like (Fig. 149); urogomphus (Fig. 151) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 shorter than any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 4) As first-instar larva except as follows: Colour. Dorsal surface of head yellowish to light brown except for several yellowish maculae on central portion of frontoclypeus, anterior to occipital suture and medial to each ocular area; ventral surface yellowish to light brown; head appendages yellowish, distal 1/2 of mandibles light brown; thoracic and, to a lesser extent abdominal sclerites with a pattern of white maculae on a yellowish to light brown background, membranous parts yellowish; legs and urogomphus yellowish to light brown. Head. Maxilla. Microspinulae lacking along inner margin of stipes.


ALARIE ET AL.

Thorax. Legs. Anteroventral spinulae strongly developed on profemur, tibiae and tarsi; metacoxa with predominantly short hair-like secondary setae along dorsal margin; metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 156). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 6; parietale with 8–10 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 155); urogomphus with secondary setae along both inner and outer margins, outer margin with a variable number of hair-like and spine-like secondary setae (cf. Fig. 156). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 3) (Figs 152–156) As second-instar larva except as follows: Colour. Dorsal surface of head greyish to light brown except for several maculae on central portion of frontoclypeus, posterior to stemmata, anterior to occipital suture and medial to each ocular area yellowish (Fig. 152); ventral surface yellow except for posterolateral areas light brown bearing several small yellowish maculae; head appendages yellowish except for apices of A3, A4, MP3 and LP2 light brown and distal 1/2 of mandible brown; thoracic and abdominal sclerites greyish to light brown, with pattern of yellowish maculae; sclerites VII and VIII without this pattern; legs yellowish; U yellowish, distal portion light brown. Thorax. Legs (Figs 153–154). Metafemoral natatory setae present along distal 1/2 of dorsal margin. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 8 and Figs 153–154; parietale with 8–10 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. As stated above (see under R. calileguai), larvae of the Neotropical species R. signatus, R. anisonychus and R. calileguai all share the presence of a variable number of both elongate hair-like and short spine-like secondary setae along the inner margin of urogomphus. Larvae of R. signatus can readily be distinguished from those of R. anisonychus and R. calileguai by the following combination of characters: size, lack of microspinulae along inner margin of stipes (second and third instar), weakly developed anteroventral spinulae on profemur (second and third instar) (Fig. 153), shorter dorsal secondary setae on metacoxa (best seen in third instar), number of natatory setae on mesofemur and metatibia (Tables 6, 8), relative elongation of LAS and urogomphus compared to HW (Tables 9–11), presence of microspinulae over posterior 1/2 of parietale basal 1/2 of urogomphus and most of anterior surface of legs, and absence on head appendages (first instar). The third-instar larva of R. signatus was previously described by Crespo (1987)

Description of larvae of Rhantus simulans Régimbart, 1908 Source of material. The larvae studied were collected in association with adults by L. Hendrich at the following locality: Western Australia. D’Entrecasteaux NP, 5 km south Northcliffe, 12 masl, 5.I.2007. Exposed, shallow pool without any vegetation but rich in rotten leaves and twigs. Larvae were sitting among the leaves right at the edge of the pool. Two species of Rhantus are present in SW Australia. The association is safe as R. simulans was the only species of Rhantus found in that pool. First- and second-instar larvae No specimens available for study. Third-instar larva (n = 2) (Figs 157–161) LARVAE OF THE GENUS RHANTUS


47

Measurements and ratios aimed to characterize body shape shown in Table 11. Colour. Body predominantly piceous black; head capsule black with a reticulate yellow colour pattern mesally over frontoclypeus and parietale (Fig. 157); head appendages yellow to piceous, A1, A2, A3, A4, MP1, MP2, MP3 and LP2 infuscate apically; body terga predominantly piceous black; protergum with an irrorate yellowish colour pattern, yellowish maculae reduced on both meso- and metatergum; abdominal terga each with a small yellowish macula mesally; abdominal segments VII and VIII paler than rest of body; legs and urogomphus yellow. Head. Maxilla. Microspinulae present along inner margin of stipes. Thorax. Legs (Figs 158–159). Anteroventral spinulae strongly developed on profemur, tibiae and tarsi; metacoxa with dorsal secondary setae predominantly elongate; metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus (Fig. 161). Fractured proximally. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 8 and Figs 158–159; parietale with 9–10 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (Fig. 160); urogomphus with secondary setae along both inner and outer margins, outer margin with elongate and hair-like setae only, except for one short spine-like seta proximally (Fig. 161). Remarks. The Australian species Rhantus simulans belongs to the group of species characterized by the presence of elongate and hair-like natatory setae and one short spine-like seta along outer margin of urogomphus (R. consputus, R. validus, R. notaticollis, R. wallisi, R. suturellus, R. suturalis, R. fennicus, R. latitans, R.exsoletus). Compared to these species, larvae of R. simulans can readily be distinguished by distribution.

Description of larvae of Rhantus socialis (C. O. Waterhouse, 1876) Source of material. The larvae studied were collected in association with adults by A. Martens at the following locality: Mascarene Islands, Rodriguez. Baleine river, near St. Gabriel, 11.VIII.2005; small stream west of Cotton Bay, 7.VIII.2005. The association is safe as R. socialis is the only species of Rhantus found in Rodriguez. First-instar larva (n = 3) (Figs 162–166) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Body predominantly pale brown; head capsule brown, paler around ocularia; head appendages yellow, A3, MP3 and LP2 infuscate apically; thoracic and abdominal terga dark yellow to pale brown; legs creamy white to pale brown; urogomphus dark yellow, dark brown proximally over a short distance. Head. Head capsule (Fig. 162). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae over most of dorsal surface. Antenna. Microspinulae lacking, antennomere III with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 163–164). Microspinulae present over most of anterior surface; tarsal claws with microspinulae covering basal 1/3 of ventral margin. Abdomen. Urogomphus (Fig. 166). Microspinulae present over most of its surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present (Fig. 162); anterior margin of frontoclypeus with 21–22 digitiform lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer


ALARIE ET AL.

and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated proximally to articulation of seta CO6; meso- and metafemoral seta FE5 elongate and hair-like (Fig. 164); seta TI7 elongate and hair-like (Fig. 164); urogomphus (Fig. 166) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 shorter than any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 2) As first-instar larva except as follows: Colour. Dorsal surface of head yellowish with a brown mottled pattern on frontoclypeus and parietale; thoracic terga yellow with an irrorate maculation pattern mesally. Head. Maxilla. Microspinulae present along inner margin of stipes. Thorax. Legs. Anteroventral spinulae weakly developed on profemur and meso- and metatibia, well developed on protibia and tarsi; metacoxa with predominantly short hair-like secondary setae along dorsal margin; metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 171). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 6; parietale with 10–12 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 170); urogomphus with secondary setae along both inner and outer margins, outer margin with a variable number of hair-like and spine-like secondary setae (cf. Fig. 171). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 3) (Figs 167–171) As second-instar larva except as follows: Colour. Darker; abdominal segments I–VI paler mesally; abdominal segment VII dark yellow. Thorax. Legs (Figs 168–169). Metafemoral natatory setae present along distal 1/2 of dorsal margin. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 8 and Figs 168–169; parietale with 10–13 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. As mentioned above, the three African species R. socialis, R. capensis and R. phocaenarum belong to a group of species characterized by the presence of a variable number of elongate hair-like and short spine-like secondary setae along the outer margin of urogomphus (Fig. 171) (along with R. signatus, R. frontalis, R. binotatus, R. calileguai, R. anisonychus). Larvae of R. socialis can be distinguished from the other two African species by the following combination of characters: smaller size, absence of microspinulae along the inner margin of stipes (second and third instar), reduced spinulae along the anteroventral margin of meso- and metatibia (second and third instar), number of natatory setae on metatibia (Tables 6, 8), relative elongation of LAS and urogomphus compared to HW (Tables 9–11) and proximal articulation of procoxal seta CO7 (first instar).

Description of larvae of Rhantus suturalis (Macleay, W.S., 1825) Source of material. The larvae studied were collected in association with adults by L. Hendrich at the following locality: Uzbekistan, Tashkent, Bektemir, 450 m, Chirchiq, floodplains, 19–21.IV.2009. The identification is safe as R. suturalis is the only Rhantus species found in Uzbekistan. First- and second-instar larvae LARVAE OF THE GENUS RHANTUS


49

No specimens available for study. Third-instar larva (n = 3) (Figs 172–176) Measurements and ratios aimed to characterize body shape shown in Table 11. Colour. Body predominantly piceous grey; head capsule piceous, with a yellow reticulate pattern mesally over frontoclypeus and parietale; occiput broadly yellow with piceous maculae mesally (Fig. 172); head appendages yellow, apices of A3, A4, MP2, MP3, and LP2 infuscate; body terga predominantly piceous to pale grey; protergum with irrorate yellow maculae mesally, broadly yellow along lateral margins; meso- and metaterga with few yellowish maculae; abdominal tergum VIII pale grey to dark yellow; legs and urogomphus yellowish. Head. Maxilla. Microspinulae lacking along inner margin of stipes. Thorax. Legs (Figs 173–174). Anteroventral spinulae strongly developed on profemur, tibiae and tarsi; metacoxa with dorsal secondary setae predominantly short; metafemoral natatory setae present along distal 2/ 3 of dorsal margin. Abdomen. Urogomphus (Fig. 176). Fractured proximally. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 8 and Figs 173–174; parietale with 7–10 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes lacking minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (Fig. 175); urogomphus with secondary setae along both inner and outer margins, outer margin with elongate and hair-like setae only, except for one short and spine-like seta proximally (cf. Fig. 176). Remarks. Rhantus suturalis belongs to the group of species characterized by the presence of elongate hair-like natatory setae and one short spine-like seta along outer margin of urogomphus (R. consputus, R. validus, R. notaticollis, R. wallisi, R. simulans, R. fennicus, R. latitans, R. exsoletus, R. suturellus). Compared to these species, larvae of R. suturalis can readily be distinguished by the following combination of characters: absence of microspinulae along inner margin of stipes, presence of short hair-like setae along dorsal margin of metacoxa, number of natatory setae on metatibia (second and third instar) (Table 6, 8), presence of one secondary seta on protrochanter, absence of PV secondary setae on tarsi (Tables 7, 8) and relative elongation of LAS and urogomphus compared to HW (Tables 9–11). The larva of this species was previously described by Galewski (1963).

Description of larvae of Rhantus suturellus (Harris, 1828) Source of material. The larvae studied were reared ex ovo by Y. Alarie from adults collected at the following locality: Canada, Québec, Lac à la Tortue, sphagnum bog, 20.IV.1988. Additional specimens were collected in association with adults by A.N. Nilsson at the following locality: Sweden, Västerbotten province, Byske, Romelsön island, bog pool, 22.VI.2003. First-instar larva (n = 2) (Figs 177–181) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Body predominantly piceous black; head capsule, head appendages and legs dark brown. Head. Head capsule (Fig. 177). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale slightly constricted at level of occipital region, with microspinulae over posterior 1/2 of dorsal surface. Antenna. Microspinulae lacking, antennomere III with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 178–179). Microspinulae reduced to dorsal margin of coxae and ventral margin of


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femora, tibiae and tarsi; tarsal claws with microspinulae covering basal 3/4 of ventral margin. Abdomen. Urogomphus (Fig. 181). Microspinulae present over most of its surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present (Fig. 177); anterior margin of frontoclypeus with 24–26 spatulate lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; meso- and metafemoral seta FE5 elongate and hair-like (Fig. 179); seta TI7 elongate and hair-like (Fig. 179); urogomphus (Fig. 181) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 as long as any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 3) As first-instar larva except as follows: Colour. A1, A2, A3, A4, LP1 and LP2 yellowish proximally. Head. Maxilla. Microspinulae lacking along inner margin of stipes. Thorax. Legs. Anteroventral spinulae strongly developed on profemur, tibiae and tarsi; metacoxa with predominantly elongate hair-like secondary setae along dorsal margin; metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 186). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 6; parietale with 7–8 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 185); urogomphus with secondary setae along both inner and outer margins, outer margin with elongate and hair-like setae only, except for one short and spine-like seta proximally (cf. Fig. 186). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 7) (Figs 182–186) As second-instar larva except as follows: Colour. Body slightly paler; head capsule dark grey with an irrorate yellowish colour pattern, occiput yellowish laterally (Fig. 182); protergum dark yellow along lateral margins, with a few yellowish maculae mesally. Thorax. Legs (Figs 183–184). Metafemoral natatory setae present along distal 1/2 of dorsal margin. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 8 and Figs 183–184; parietale with 8–12 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. The Holarctic Rhantus suturellus belongs to the group of species characterized by the presence of elongate hair-like natatory setae and one short spine-like seta along outer margin of urogomphus (R. consputus, R. validus, R. notaticollis, R. wallisi, R. simulans, R. fennicus, R. latitans, R. exsoletus, R. suturalis). Compared to these species, larvae of R. suturellus can readily be distinguished by the following combination of characters: absence of microspinulae along inner margin of stipes (second and third instar), presence of elongate hair-like setae along the dorsal margin of metacoxa (best seen in third instar), number of natatory setae on metatibia (second and third instar) (Table 6, 8), relative elongation of LAS and urogomphus compared to HW (Tables 9–11), lamellae clypeales spatulate (first instar) (Fig. 177), absence of additional setae along the inner margin of stipes (first instar), distal articulation of procoxal seta CO7 (first instar), presence of additional setae along dorsal margin of pro- and mesotibia, and of at least two ventral additional setae on tarsi (first instar) (Figs 178–179, Table 4), microspinulae reduced on coxae and femora, wellLARVAE OF THE GENUS RHANTUS


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developed on urogomphus (first instar). All instars of this species were described previously by Galewski (1963). The third-instar larva was possibly first described by Bertrand (1928) under the name R. bistriatus (Bergsträsser) (Galewski 1963). Description of larvae of Rhantus validus Sharp, 1882 Source of material. Larvae were collected in association with adults by M. Archangelsky and M.C. Michat at the following locality: Argentina, Chubut province, stream arising from Laguna La Z, surroundings of Esquel City, 2003. First-instar larva (n = 1) (Figs 187–195) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour. Dorsal surface of cephalic capsule brown except for one light brown macula enclosing each egg burster; head appendages testaceous to light brown; thoracic and abdominal tergites testaceous to light brown; legs testaceous to light brown except for coxae somewhat paler and medial portion of trochanter testaceous; urogomphus testaceous to light brown. Head. Head capsule (Fig. 187). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale distinctly constricted at level of occipital region, with microspinulae over most of dorsal surface. Antenna. Microspinulae lacking, antennomere III with a ventroapical spinula. Maxilla (Figs 192–193). Palpus lacking microspinulae. Labium (Figs 194–195). Palpus lacking microspinulae. Thorax. Legs (Figs 188–189). Microspinulae present all over surface; tarsal claws with microspinulae covering basal 3/4 of ventral margin. Abdomen. Urogomphus (Fig. 191). Microspinulae present over most of its surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe absent (Fig. 187); anterior margin of frontoclypeus with 34–35 spatulate lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 elongate, subequal in length to galea (Fig. 193); primary seta MX5 shorter than galea, longer than palpifer (Fig. 192); stipes with one additional seta along inner margin (Fig. 192); anterodorsal primary setae of prementum elongate (Fig. 194); procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; meso- and metafemoral seta FE5 short and spine-like (Fig. 189); seta TI7 elongate and hair-like (Fig. 189); urogomphus (Fig. 191) with several additional seta; relative length of setae UR2–UR8 not defined owing to presence of several additional setae similar in size. Second-instar larva (n = 1) As first-instar larva except as follows: Colour. Darker; head capsule with an irrorate yellowish colour pattern dorsally; occiput with one mesal and two lateral yellow maculae. Head. Maxilla. Microspinulae present along inner margin of stipes. Thorax. Legs. Anteroventral spinulae strongly reduced on profemur, well-developed on tibiae and tarsi; metacoxae with predominantly elongate hair-like secondary setae along dorsal margin; metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Not fractured proximally (cf. Fig. 200). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 6; parietale with 10–11 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with elongate spine-like secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 199); urogomphus with secondary setae along both inner and outer margins, outer margin with elongate and hair-like setae only, except for one short and spine-like seta proximally (cf. Fig. 200). Measurements and ratios aimed to characterize body shape shown in Table 10.


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Third-instar larva (n = 1) (Figs 196–200) As second-instar larva except as follows: Colour. Dark brown; A1, A2, A3, A4, MP2, MP3 and LP2 paler proximally. Thorax. Legs (Figs 197–198). Metafemoral natatory setae present along distal 1/2 of dorsal margin. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 8 and Figs 197–198; parietale with 13 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. Larvae of the Neotropical R. validus are characterized by several unique features within Rhantus. In addition to their large size, larvae are characterized by the presence of elongate and spine-like setae along inner margin of stipes (Fig. 192) (shared with R. calidus), elongate setae along anterodorsal margin of prementum (Fig. 194) (shared with R. grapii), larger number of lamellae clypeales (first instar), longer primary setae MX5 and MX7 (Figs 192–193), and presence of several additional setae on urogomphus (first instar) (Fig. 191).

Description of larvae of Rhantus wallisi Hatch, 1953 Source of material. The larvae studied were reared ex ovo by Y. Alarie from adults collected at the following locality: Canada, Ontario, Sudbury, Lake Laurentian Conservation Area, pond, 20.V.1998; Manitoulin Island, roadside ditch at Hwy 540, 9 km east of Mildrum Bay, 17.V.2001. First-instar larva (n = 5) (Figs 201–205) Measurements and ratios aimed to characterize body shape shown in Table 9. Colour (freshly killed specimens). Body yellow to piceous; head capsule testaceous, with a cloudy light grey pattern over frontoclypeus and parietale; head appendages greyish black except MP1 and LP1 yellow; thoracic terga grey, faintly yellow; abdominal terga grey; legs yellowish grey; urogomphus dark grey. Head. Head capsule (Fig. 201). Frontoclypeus extending beyond tips of adnasaliae, lacking microspinulae over dorsal surface; adnasaliae converging inward; occipital carina well defined; parietale slightly constricted at level of occipital region, with microspinulae over posterior 1/2 of dorsal surface. Antenna. Microspinulae lacking; antennomere III with a ventroapical spinula. Maxilla. Palpus lacking microspinulae. Labium. Palpus lacking microspinulae. Thorax. Legs (Figs 202–203). Microspinulae reduced to dorsal margin of coxae and ventral margin of femora, tibiae and tarsi; tarsal claws with microspinulae covering basal 2/3 of ventral margin. Abdomen. Urogomphus (Fig. 205). Microspinulae present over most of its surface. Chaetotaxy. Position and number of additional setae on legs are shown in Table 4; primary pore FRe present (Fig. 201); anterior margin of frontoclypeus with 24–25 spatulate lamellae clypeales; A3 with two additional ventroapical pores; primary seta MX7 shorter than galea; primary seta MX5 shorter than palpifer and galea; stipes lacking additional setae along inner margin; anterodorsal primary setae of prementum minute; procoxal seta CO7 articulated distally, at about level of articulation of seta CO6; meso- and metafemoral seta FE5 elongate and hair-like (Fig. 203); seta TI7 elongate and hair-like (Fig. 203); urogomphus (Fig. 205) with one additional seta; primary seta UR2 about as long as seta UR3; primary seta UR4 as long as any of setae UR5, UR6 or UR8; seta UR5 articulated posterior to articulation of seta UR7; seta UR7 shorter than any of setae UR5, UR6 or UR8. Second-instar larva (n = 5) As first-instar larva except as follows: Colour. Predominantly testaceous; head capsule with a narrow blackish stripe along coronal suture and LARVAE OF THE GENUS RHANTUS


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lateral margins of parietale; head appendages piceous black, most articles darker apically; thoracic and abdominal terga I-VII yellowish, with a faint greyish pattern mesally, black along sutural line and postscutellum; last abdominal segment piceous over siphon; legs predominantly yellowish; urogomphus piceous black, yellowish proximally. Head. Maxilla. Microspinulae lacking along inner margin of stipes. Thorax. Legs. Anteroventral spinulae strongly developed on profemur, tibiae and tarsi; metacoxa with predominantly elongate hair-like secondary setae along dorsal margin; metafemoral natatory setae present along distal 1/2 of dorsal margin. Abdomen. Urogomphus. Fractured proximally (cf. Fig. 210). Chaetotaxy. Number and position of secondary setae on legs are shown in Table 6; parietale with 7–11 temporal spine-like setae, most anterior ones articulated at about level of posterior margin of ocularium; stipes with minute secondary setae along inner margin; dorsal surface of last abdominal segment covered with both spine-like and hair-like secondary setae (cf. Fig. 209); urogomphus with secondary setae along both inner and outer margins, outer margin with elongate and hair-like setae only, except for one short and spine-like seta proximally (Fig. 210). Measurements and ratios aimed to characterize body shape shown in Table 10. Third-instar larva (n = 7) (Figs 206–210) As second-instar larva except as follows: Colour. Body yellow; most body terga with an irrorate greyish pattern; head appendages predominantly yellow, A1, A2, A3, MP2, MP3 and LP2 piceous apically, A4 all piceous; legs yellow; urogomphus predominantly yellow, piceous apically. Thorax. Legs (Figs 207–208). Metafemoral natatory setae present along distal 1/2 of dorsal margin. Chaetotaxy. Number and position of secondary setae on legs are shown in Table 8 and Figs 207–208; parietale with 8–11 temporal spine-like setae. Measurements and ratios aimed to characterize body shape shown in Table 11. Remarks. The Nearctic R. wallisi belongs to the group of species characterized by the presence of elongate and hair-like natatory setae and one shorter spine-like seta along the outer margin of urogomphus (Fig. 210) (R. consputus, R. validus, R. notaticollis, R. suturellus, R. suturalis, R. simulans, R. fennicus, R. latitans, R. exsoletus). In the Nearctic region, larvae of this species can only be confused with those of R. suturellus, from which they can be distinguished by the characters mentioned in the key (see also under R. suturellus).

Character Analysis The analysis of the data matrix using TNT resulted in 4800 most parsimonious trees of 111 steps. The strict consensus was calculated (Fig. 211). The second analysis using implied weighting produced 1400 trees, the consensus of which showed a better resolution than the previous analysis (Fig. 212). In both analyses, the support obtained was high for the Colymbetini clade but low for the internal nodes.

Discussion Based on this study, the monophyly of the Colymbetini is indicated by at least five synapomorphies (i.e., found only in this group and unreversed) in regard of outgroups chosen. Larvae of Colymbetini have evolved (i) a relatively more distal articulation of the primary pore ANg on antennomere IV (character 07), (ii) a much reduced sensorial appendage (A3’) (character 10), (iii) a relatively more proximal articulation of the primary


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seta FE1 (character 32), (iv) the presence of tarsal claw basoventral spinulae in first instar (character 43) (whereas tarsal spinulae are sometimes reduced or lacking in instar III of some species, this study suggests that they always occur in the first instar), and (v) the presence of a one-segmented urogomphus (character 53). It is noteworthy that larvae of the Colymbetini are also characterized by (i) the presence of additional ventroapical pores on antennomere III (character 12), (ii) elongate and hair-like primary seta FE6 (character 36) and (iii) the presence of secondary natatory setae on legs (character 46). These three character states are considered of a lesser evolutionary meaning knowing that they have evolved several times independently within the Dytiscidae, namely in Lancetes Sharp (Alarie et al. 2002; Alarie & Hughes 2006). The present paper represents the most comprehensive study of the larval morphology of world species of Rhantus ever published, which incorporates species from all major zoogeographic regions (Table 1). Interestingly, our phylogenetic analysis (Fig. 212) suggests that Rhantus is polyphyletic in agreement with recent studies based on adult (Miller 2001), larval (Alarie & Hughes 2006; Michat 2005) and molecular (Ribera et al. 2008) data sets. Indeed, larvae of this genus reveal to be fairly diverse morphologically, which resulted into closer relationships of Rhantus monteithi and R. grapii with some other genera of the Colymbetini than other species of the genus (Figs 211–212). Larvae of R. grapii differ strongly from those of any other Rhantus species studied by the following unique character states: (i) frontoclypeus extending beyond adnasaliae (character 05) (Fig. 101), (ii) adnasaliae diverging outward (character 06) (Fig. 101), (iii) antennomere 3 lacking a ventral spinula (character 11), (iv) primary seta MX5 longer than labial palpomere 1 (character 18) (Fig. 102), (v) galea elongate (character 20) (Fig. 102), (vi) presence of additional setae along dorsal margin of femur (character 33) (Fig. 103), and (vii) primary seta UR2 longer than seta UR3 (character 55) (Fig. 106). Larval morphology clearly reinforces the hypothesis that R. grapii belongs to a distinct lineage within the Colymbetini as indicated in previous studies based on adult (Nilsson 2001) and molecular data sets (Ribera et al. 2008). In that regard a study of the larval morphology of R. sinuatus (LeConte), with R. grapii the only other Rhantus species placed in the subgenus Nartus Zaitzev would be of the utmost interest. Whereas the tree topologies presented in this paper (Figs 211–212) are hampered by weak node supports, some hypotheses warrant to be discussed. First, we suggest that the Neotropical species R. orbignyi, R. antarcticus, R. calidus and R. validus may represent a distinct lineage within the Colymbetini. All these species diverge at the basis of the trees prior to all other Colymbetini studied and are characterized by several unique larval character states: (i) the absence of the primary pore FRe (character 02) (Figs 1, 40, 127, 187), the short and spine-like aspect of (ii) the meso- and (iii) metafemoral seta FE5 (characters 34 and 35) (Figs 11, 42, 129, 189) and the absence of additional setae both on (iv) protibia (character 37) and (v) tarsus (character 41) (Figs 10–11, 41–42, 128–129, 188–189). All these species but R. validus also are characterized by a short and spine-like primary seta TI7 (character 40) (Figs 10–11, 41–42, 128–129) and by the absence of secondary setae on urogomphi (character 51) (Figs 19, 50, 136), two unique features within the Colymbetini. Among these species, R. calidus stands as the most divergent species being characterized by the secondary subdivision of (i) the antennomeres 2–4 (character 14) (Fig. 46), (ii) the maxillary palpomeres 2–3 (character 17), and (iii) the labial palpomere 2 (character 26) and the articulation of the primary seta UR5 anterior to seta UR7 (character 57) (Fig. 44). Larvae of both R. calidus and R. validus share the presence of three elongate setae along inner margin of stipes (character 21) (Figs 192–193) and the presence of several elongate setae on the prementum (character 28) (Figs 194–195) (possibly homoplastic in R. grapii). The Pacific species R. poellerbaurae and R. monteithi diverged at the basis of our trees, closer to other Colymbetini genera (namely Carabdytes upin Balke, Hendrich & Wewalka, 1992) in accordance with a recent study based on molecular data (Balke et al. 2009). In the absence of first instar for each of these species, however, such hypothesis is weakly supported since several of the characters used in this study are from firstinstar larvae. Our study also suggests that the bulk of the Rhantus species studied (18 of 24) may be closely related phylogenetically. With few exceptions (R. simulans, R. calileguai, R. phocaenarum, R. socialis), all these species have a Nearctic and/or Palearctic distribution. Larvae of these species are characterized by (i) the presence of an elongate and hair-like meso- and metafemoral seta FE5 (characters 34 and 35) (Figs 22, 32, 53, LARVAE OF THE GENUS RHANTUS


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68, 78, 88, 119, 149, 164, 179, 203), and the presence of additional setae on (ii) protibia (character 37), (iii) tarsus (character 41) (Figs 21–22, 31–32, 52–53, 67–68, 77–78, 87–88, 118–119, 148–149, 163–164, 178– 179, 202–203) and (iv) metafemur (character 42) (Figs 22, 32, 53, 68, 78, 88, 119, 149, 164, 179, 203) (homoplastic in R. grapii and some Colymbetini genera). Among these, larvae of R. signatus, R. phocaenarum, R. frontalis, R. capensis, R. calileguai, R. binotatus, R. anisonychus, R. socialis, and R. formosanus all share the presence of a variable number of spiniform secondary setae along the outer margin of urogomphus (character 50) (Figs 29, 39, 60, 65, 100, 146, 156, 171) and the presence of seta UR4 shorter than setae UR5, UR6 and UR8 (character 56, only seen in first-instar larvae) (Figs 24, 34, 55, 141, 151, 166). A closer phylogenetic relationship of Palearctic and Nearctic elements of Rhantus is in accordance with a recent study based on molecular data (Balke et al. 2009).

Acknowledgements Financial support was provided by the Natural Sciences and Engineering Research Council of Canada in the form of an operating research grant to Y.A. Field and laboratory work by M.C.M. was supported in part by grant PIB X846 from the Universidad de Buenos Aires and a postgraduate scholarship from CONICET. Field work by M.A. was partially supported by the grant PICT 01–06156 from the ‘Agencia Nacional de Promociones Cientificas Técnicas (Argentina); this is contribution No 29 from LIESA. Field work by L.H. was supported by Deutsche Forschungsgemeinschaft grant BA 2152/4-1 to Dr M. Balke (Zoologische Staatssammlung, Munich, Germany).

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Paillart, 804 pp. Brinck, P. (1943) Nomenklatorische und systematische Studien über Dytisciden. Kungliga Fysiografiska Sällskapets i Lund Förhandlingar, 13(13), 1–13. Brinck, P. (1948) Coleoptera of Tristan da Cunha. Results of the Norwegian Scientific Expedition to Tristan da Cunha 1937–1938, 17, 1–121 + 1pl. Clairville, J.P. de (1806) In: Clairville J.P. & Schellenberg J.R. Entomologie helvétiqueou catalogue des insectes de la Suisse, rangés d’après une nouvelle méthode, avec descriptions et figures. Vol. 2. Zürich, Orell, Fussli et Co., xliii + 247 pp. + 32 pls. Costa, C., Vanin, S.A. & Casari-Chen, S.A. (1988) Larvas de Coleoptera do Brasil. Saõ Paulo, 282 pp. + 165 plates. Crespo F.A. (1987) Los estados preimaginales de ditíscidos argentinos (Insecta-Coleoptera). Tesis de Doctorado, Universidad de Buenos Aires, iii + 184 pp. Crotch, G.R. (1873) Revision of the Dytiscidae of the United States. Transactions of the American Entomological Society, 4, 383–424. Dejean, P.F.M.A. (1833) Catalogue des coléoptères de la collection de M. Le comte Dejean. Livraison 1 & 2. Paris, Méquignon-Marvis, 176 pp. Fabricius, J.C. (1775) Systema entomologiae, sistens Insectorum classses. Ordinen, genera, species adiectis synonymis, locis, descriptionibus, observationibus. Flensburgi et Lipsiae, Libraria Korte, xxxii + 832 pp. Fabricius, J.C. (1792–1794) Entomologia systematica emendata et aucta. Secundum classes, ordines, genera, species adjectis, synonimis, locis, observationibus, descriptionibus. 4 vols. Hafniae, C.G. Proft (Vol. 1: part 1, xx + 330 pp., 1792; part 2, 538 pp., 1793; vol. 3: part 1. vi + 487 pp., 1793; part 2. 349 pp., 1794; vol. 4. vi + 472 pp., [1794]. Fall, H.C. (1927) A new genus and species of Dytiscidae. Journal of the New York Entomological Society, 35, 177–178. Forster, J.R. (1771) Novae species Insectorum. Centuria I. Nam mihi contuenti se persuasit rerum nature, nihil incredible existimare de ea. Londini, T. Davies & B. White, viii + 100 pp. Galewski, K. (1963) Immature stages of the Central European species of Rhantus Dejean (Coleoptera, Dytiscidae). Polskie Pismo Entomologiczne, 33, 3–93. Guignot, F. (1957) Dytiscides et gyrinides de l’Île de la Réunion. Mémoires de l’Institut Scientifique de Madagascar (E), 8, 97–101. Goloboff, P., Farris, J. & Nixon, K. (2008) TNT, a free program for phylogenetic analysis. Cladistics, 24, 774–786. Gyllenhal, L. (1808) Insecta Suecica descripta. Classis I. Coleoptera sive Eleutherata. Vol. 1.Part 1. Scaris, F.J. Leverentz, xii + 572 pp. Harris, T.W. (1828) Contributions to entomology. No. VI. New England Farmer, 7(21), 164. Hatch, M.H. (1953) The beetles of the Pacific Northwest. Part I: Introduction and Adephaga. University of Washington Publications in Biology, 16, 1–340. Huldén, L. (1982) Rhantus fennicus sp. n. (Coleoptera: Dytiscidae) from Finland. Notulae Entomologicae, 62, 125–127. James, H.G. (1969) Immature stages of five diving beetles (Coleoptera: Dytiscidae), notes on their habits and life history, and key to aquatic beetles of vernal woodland pools in southern Ontario. Proceedings of the Entomological Society of Ontario, 100, 52–97. Kamiya, K. (1938) A systematic study of the Japanese Dytiscidae. Journal of the Tokyo Agricultural University, 5, 1–68 + 7 pls. Kitching, I.J., Forey, P.L., Humphries, C.J. & Williams, D.M. (1998) Cladistics, Second Edition. The theory and practice of parsimony analysis. Systematic Association publications, 11. New York, Oxford University Press,. 228 pp. Klausnitzer, B. (1991) Die Larven der Käfer Mitteleuropas. 1. Band Adephaga. Krefeld, Goecke & Evers, 273 pp. Kögel, F. (1987) Zur Biologie und Ökologie von Rhantus consputus Sturm (Coleoptera, Dytiscidae). Entomologische Arbeiten aus dem Museum G. Frey, 25/36, 5–19. Laporte, F.L. (1834–1835) Études entomologiques. Première partie. Paris, Méquignon-Marvis Père et Fils, 159 pp. (Pp. 1–94 1834; 95–159 1835) Lawrence, J.F. (1991) Order Coleoptera. In: Stehr, F.W. (ed.) Immature insects, volume 2. Iowa, Kendall/Hunt Publishing Company, pp. 144–658. Marsham, T. (1802) Entomologia Britannica. Vol. I. Coleoptera. Londini, xxxi + 548 pp.



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Meinert, F. (1901) Sur les larves de dytiscides (larvae Dytiscidarum). Det Kongelike Danske Videnskabernes Selskabs Skrifter, Naturvidenskabelig og Mathematisk Afdeling (6) n8): 341–440 + pls. I–VI. [in Danish] Michat, M.C. (2005) Larval morphology and phylogenetic relationships of Bunites distigma (Brullé) (Coleoptera: Dytiscidae: Colymbetinae: Colymbetini). The Coleopterists Bulletin, 59, 433–447. Miller, K.B. (2001) On the phylogeny of the Dytiscidae (Insecta: Coleoptera) with emphasis on the morphology of the female reproductive system. Insect Systematics & Evolution, 32, 45–92. Nilsson, A.N. (1987) The larva of Rhantus fennicus (Coleoptera, Dytiscidae), with a key to the Fennoscandian species of Rhantus. Notulae Entomologicae, 67, 33–41. Nilsson, A.N. (2001) World Catalogue of Insects, volume 3: Dytiscidae (Coleoptera). Stenstrup, Apollo Books, 395 pp. Nilsson, A.N. & Hilsenhoff, W.L. (1991) Review of first-instar larvae of Colymbetini (Coleoptera: Dytiscidae), with a key to genera and phylogenetic analysis. Entomologica Scandinavica, 22, 35–44. Régimbart, M. (1908) Dytiscidae, Gyrinidae et Hydrophilidae. Die Fauna Südwest-Australiens. Ergebnisse der hamburger südwestaustralischen Forschungreise 1905, herausgegeben von Prof. W. Michaelsen und Dr. R. Hartmeyer, 1(8), 309–316. Ribera, I., Vogler, A.P & Balke, M. (2008) Phylogeny and diversification of diving beetles (Coleoptera: Dytiscidae). Cladistics, 24, 563–590. Seidlitz, G. (1887) Bestimmungs-Tabelle der Dytiscidae und Gyrinidae des europäischen Faunengebietes. Verhandlungen des Naturforschenden Vereines in Brünn, 25(1886), 3–136. Sharp, D. (1882) On aquatic carnivorous Coleoptera or Dytiscidae. The Scientific Transactions of the Royal Dublin Society, (2)2, 179–1003 + pls. 7–18. Spangler, P.J. (1972) A new genus and new species of water beetle from Bolivia with a key to the genera of the Western Hemisphere Colymbetini (Coleoptera: Dytiscidae). Proceedings of the Biological Society of Washington, 86: 423– 434. Sturm, J. (1834) Deutschlands Faune in Abbildungen nach der Natur mit Beschreibungen. Abt. V. Die Insecten. Volume 9, Käfer. Nürnberg. Privately printed, vi + 170 pp. + pls. CLXXXV–CCII. Trémouilles, E.R. (1984) El género Rhantus Dejean en la Argentina (Coleoptera, Dytiscidae). Physis (Buenos Aires), Secc. B, 42(102), 9–24. Waterhouse, C.O. (1876) New species of Coleoptera from the Island of Rodriguez, collected by naturalists accompanying the Transit-of-Venus Expedition. The Annals and Magazine of Natural History, (4)18, 105–121. Watts, C.H.S. (1963) The larvae of Australian Dytiscidae (Coleoptera). Transactions of the Royal Society of South Australia, 87, 23–40. Williams, F.N. (1936) Biological studies in Hawaiian water-loving insects. Proceedings of the Hawaiian Entomological Society, 9, 235–273. Zimmerman, J.R. & Smith, R.L. (1975) The genus Rhantus (Coleoptera: Dytiscidae) in North America. Part I. General account of the species. Transactions of the American Entomological Society, 101, 651–722.


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FIGURES 1–2. Rhantus antarcticus nahueli (first-instar larva), head capsule: (1) dorsal aspect (colour pattern not represented); (2) ventral aspect. EB, egg bursters: FR, frontoclypeus; PA, parietale; TP, tentorial pits. Numbers and lowercase letters refer to primary setae and pores, respectively. Scale bar = 0.20 mm.



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FIGURES 3–9. Rhantus antarcticus nahueli (first-instar larva), head appendages: (3–4) antenna, (3) dorsal aspect; (4) ventral aspect; (5–6) maxilla, (5) dorsal aspect; (6) ventral aspect; (7–8) labium; (7) dorsal aspect; (8) ventral aspect; (9) mandible, dorsal aspect. AN, antenna; LA, labium; MN, mandible; MX, maxilla. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares and triangles refer to additional setae and pores, respectively. Scale bars = 0.10 mm.


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FIGURES 10–14. Rhantus antarcticus nahueli (first-instar larva): (10–11) metathoracic leg; (10) anterior aspect; (11) posterior aspect; (12–13) abdominal segment eight; (12) dorsal aspect; (13) ventral aspect; (14) urogomphus, dorsal aspect; AB, abdominal segment eight; CO, coxa; FE, femur; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.



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FIGURES 15–19. Rhantus antarcticus nahueli (third-instar larva): (15) head capsule, dorsal aspect (not all secondary setae represented); (16–17) prothoracic leg; (16) anterior aspect; (17) posterior aspect; (18) abdominal segment eight, dorsal aspect; (19) urogomphus, dorsal aspect. Scale bars = 0.50 mm.


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FIGURES 20–24. Rhantus anisonychus (first-instar larva): (20) head capsule, dorsal aspect (colour pattern not represented); (21–22) metathoracic leg; (21) anterior aspect; (22) posterior aspect; (23) abdominal segment eight, dorsal aspect; (24) urogomphus, dorsal aspect. AB, abdominal segment eight; CO. coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter, UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.



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FIGURES 25–29. Rhantus anisonychus (third-instar larva): (25) head capsule, dorsal aspect (not all secondary setae represented); (26–27) prothoracic leg; (26) anterior aspect; (27) posterior aspect; (28) abdominal segment eight, dorsal aspect; (29) urogomphus, dorsal aspect. Scale bars = 0.50 mm.


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FIGURES 30–34. Rhantus binotatus (first-instar larva): (30) head capsule, dorsal aspect (colour pattern not represented); (31–32) metathoracic leg; (31) anterior aspect; (32) posterior aspect; (33) abdominal segment eight, dorsal aspect; (34) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.



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FIGURES 35–39. Rhantus binotatus (third-instar larva): (35) head capsule, dorsal aspect (not all secondary setae represented); (36–37) prothoracic leg; (36) anterior aspect; (37) posterior aspect; (38) abdominal segment eight, dorsal aspect; (39) urogomphus, dorsal aspect. Scale bars = 0.50 mm.


ALARIE ET AL.

FIGURES 40–44. Rhantus calidus (first-instar larva): (40) head capsule, dorsal aspect (colour pattern not represented); (41–42) metathoracic leg; (41) anterior aspect; (42) posterior aspect; (43) abdominal segment eight, dorsal aspect; (44) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.



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FIGURES 45–50. Rhantus calidus (third-instar larva): (45) head capsule, dorsal aspect (not all secondary setae represented); (46) antenna, dorsal aspect; (47–48) prothoracic leg; (47) anterior aspect; (48) posterior aspect; (49) abdominal segment eight, dorsal aspect; (50) urogomphus, dorsal aspect. Scale bars = 0.50 mm.


ALARIE ET AL.

FIGURES 51–55. Rhantus calileguai (first-instar larva): (51) head capsule, dorsal aspect (colour pattern not represented); (52–53) metathoracic leg; (52) anterior aspect; (53) posterior aspect; (54) abdominal segment eight, dorsal aspect; (55) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.15 mm.



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FIGURES 56–60. Rhantus calileguai (third-instar larva): (56) head capsule, dorsal aspect (not all secondary setae represented); (57–58) prothoracic leg; (57) anterior aspect; (58) posterior aspect; (59) abdominal segment eight, dorsal aspect; (60) urogomphus, dorsal aspect. Scale bars = 0.50 mm.


ALARIE ET AL.

FIGURES 61–65. Rhantus capensis (third-instar larva): (61) head capsule, dorsal aspect (not all secondary setae represented); (62–63) prothoracic leg; (62) anterior aspect; (63) posterior aspect; (64) abdominal segment eight, dorsal aspect; (65) urogomphus, dorsal aspect. Scale bars = 0.50 mm.



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FIGURES 66–70. Rhantus consputus (first-instar larva): (66) head capsule, dorsal aspect (colour pattern not represented); (67–68) metathoracic leg; (67) anterior aspect; (68) posterior aspect; (69) abdominal segment eight, dorsal aspect; (70) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.


ALARIE ET AL.

FIGURES 71–75. Rhantus consputus (third-instar larva): (71) head capsule, dorsal aspect (not all secondary setae represented); (72–73) prothoracic leg; (72) anterior aspect; (73) posterior aspect; (74) abdominal segment eight, dorsal aspect; (75) urogomphus, dorsal aspect. Scale bars = 0.50 mm.



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FIGURES 76–80. Rhantus exsoletus (first-instar larva): (76) head capsule, dorsal aspect (colour pattern not represented); (77–78) metathoracic leg; (77) anterior aspect; (78) posterior aspect; (79) abdominal segment eight, dorsal aspect; (80) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia: TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.


ALARIE ET AL.

FIGURES 81–85. Rhantus exsoletus (third-instar larva): (81) head capsule, dorsal aspect (not all secondary setae represented); (82–83) prothoracic leg; (82) anterior aspect; (83) posterior aspect; (84) abdominal segment eight, dorsal aspect; (85) urogomphus, dorsal aspect. Scale bars = 0.50 mm.



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FIGURES 86–90. Rhantus fennicus (first-instar larva): (86) head capsule, dorsal aspect (colour pattern not represented); (87–88) metathoracic leg; (87) anterior aspect; (88) posterior aspect; (89) abdominal segment eight, dorsal aspect; (90) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus, TI, tibia: TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.


ALARIE ET AL.

FIGURES 91–95. Rhantus fennicus (third-instar larva): (91) head capsule, dorsal aspect (not all secondary setae represented); (92–93) prothoracic leg; (92) anterior aspect; (93) posterior aspect; (94) abdominal segment eight, dorsal aspect; (95) urogomphus, dorsal aspect. Scale bars = 0.50 mm.



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FIGURES 96–100. Rhantus frontalis (third-instar larva): (96) head capsule, dorsal aspect (not all secondary setae represented); (97–98) prothoracic leg; (97) anterior aspect; (98) posterior aspect; (99) abdominal segment eight, dorsal aspect; (100) urogomphus, dorsal aspect. Scale bars = 0.50 mm.


ALARIE ET AL.

FIGURES 101–106. Rhantus grapii (first-instar larva): (101) head capsule, dorsal aspect (colour pattern not represented); (102) maxilla, ventral aspect; (103–104) metathoracic leg; (103) anterior aspect; (104) posterior aspect; (105) abdominal segment eight, dorsal aspect; (106) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.



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FIGURES 107–111. Rhantus grapii (third-instar larva): (107) head capsule, dorsal aspect (not all secondary setae represented); (108–109) prothoracic leg; (108) anterior aspect; (109) posterior aspect; (110) abdominal segment eight, dorsal aspect; (111) urogomphus, dorsal aspect. Scale bars = 0.50 mm.


ALARIE ET AL.

FIGURES 112–116. Rhantus latitans (third-instar larva): (112) head capsule, dorsal aspect (not all secondary setae represented); (113–114) prothoracic leg; (113) anterior aspect; (114) posterior aspect; (115) abdominal segment eight, dorsal aspect; (116) urogomphus, dorsal aspect. Scale bars = 0.50 mm.



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FIGURES 117–121. Rhantus notaticollis (first-instar larva): (117) head capsule, dorsal aspect (colour pattern not represented); (118–119) metathoracic leg; (118) anterior aspect; (119) posterior aspect; (120) abdominal segment eight, dorsal aspect; (121) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.


ALARIE ET AL.

FIGURES 122–126. Rhantus notaticollis (third-instar larva): (122) head capsule, dorsal aspect (not all secondary setae represented); (123–124) prothoracic leg; (123) anterior aspect; (124) posterior aspect; (125) abdominal segment eight, dorsal aspect; (126) urogomphus, dorsal aspect. Scale bars = 0.50 mm.



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FIGURES 127–131. Rhantus orbignyi (first-instar larva): (127) head capsule, dorsal aspect (colour pattern not represented); (128–129) metathoracic leg; (128) anterior aspect; (129) posterior aspect; (130) abdominal segment eight, dorsal aspect; (131) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.15 mm (Fig. 127) and 0.20 mm.


ALARIE ET AL.

FIGURES 132–136. Rhantus orbignyi (third-instar larva): (132) head capsule, dorsal aspect (not all secondary setae represented); (133–134) prothoracic leg; (133) anterior aspect; (134) posterior aspect; (135) abdominal segment eight, dorsal aspect; (136) urogomphus, dorsal aspect. Scale bars = 0.50 mm.



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FIGURES 137–141. Rhantus phocaenarum (first-instar larva): (137) head capsule, dorsal aspect (colour pattern not represented); (138–139) metathoracic leg; (138) anterior aspect; (139) posterior aspect; (140) abdominal segment eight, dorsal aspect; (141) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa: EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.


ALARIE ET AL.

FIGURES 142–146. Rhantus phocaenarum (third-instar larva): (142) head capsule, dorsal aspect (not all secondary setae represented); (143–144) prothoracic leg; (143) anterior aspect; (144) posterior aspect; (145) abdominal segment eight, dorsal aspect; (146) urogomphus, dorsal aspect. Scale bars = 0.50 mm.



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FIGURES 147–151. Rhantus signatus (first-instar larva): (147) head capsule, dorsal aspect (colour pattern not represented); (148–149) metathoracic leg; (148) anterior aspect; (149) posterior aspect; (150) abdominal segment eight, dorsal aspect; (151) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.15 mm.


ALARIE ET AL.

FIGURES 152–156. Rhantus signatus (third-instar larva): (152) head capsule, dorsal aspect (not all secondary setae represented); (153–154) prothoracic leg; (153) anterior aspect; (154) posterior aspect; (155) abdominal segment eight, dorsal aspect; (156) urogomphus, dorsal aspect. Scale bars = 0.50 mm.



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FIGURES 157–161. Rhantus simulans (third-instar larva): (157) head capsule, dorsal aspect (not all secondary setae represented); (158–159) prothoracic leg; (158) anterior aspect; (159) posterior aspect; (160) abdominal segment eight, dorsal aspect; (161) urogomphus, dorsal aspect. Scale bars = 0.50 mm.


ALARIE ET AL.

FIGURES 162–166. Rhantus socialis (first-instar larva): (162) head capsule, dorsal aspect (colour pattern not represented); (163–164) metathoracic leg; (163) anterior aspect; (164) posterior aspect; (165) abdominal segment eight, dorsal aspect; (166) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus, TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.



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FIGURES 167–171. Rhantus socialis (third-instar larva): (167) head capsule, dorsal aspect (not all secondary setae represented); (168–169) prothoracic leg; (168) anterior aspect; (169) posterior aspect; (170) abdominal segment eight, dorsal aspect; (171) urogomphus, dorsal aspect. Scale bars = 0.50 mm.


ALARIE ET AL.

FIGURES 172–176. Rhantus suturalis (third-instar larva): (172) head capsule, dorsal aspect (not all secondary setae represented); (173–174) prothoracic leg; (173) anterior aspect; (174) posterior aspect; (175) abdominal segment eight, dorsal aspect; (176) urogomphus, dorsal aspect. Scale bars = 0.50 mm.



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FIGURES 177–181. Rhantus suturellus (first-instar larva): (177) head capsule, dorsal aspect (colour pattern not represented); (178–179) metathoracic leg; (178) anterior aspect; (179) posterior aspect; (180) abdominal segment eight, dorsal aspect; (181) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus, TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.


ALARIE ET AL.

FIGURES 182–186. Rhantus suturellus (third-instar larva): (182) head capsule, dorsal aspect (not all secondary setae represented); (183–184) prothoracic leg; (183) anterior aspect; (184) posterior aspect; (185) abdominal segment eight, dorsal aspect; (186) urogomphus, dorsal aspect. Scale bars = 0.50 mm.



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FIGURES 187–191. Rhantus validus (first-instar larva): (187) head capsule, dorsal aspect (colour pattern not represented); (188–189) metathoracic leg; (188) anterior aspect; (189) posterior aspect; (190) abdominal segment eight, dorsal aspect; (191) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares and triangles refer to additional setae and pores, respectively. Scale bars = 0.20 mm.


ALARIE ET AL.

FIGURES 192–195. Rhantus validus, (first-instar larva), head appendages: (192–193) maxilla; (192) dorsal aspect; (193) ventral aspect; (194–195) labium; (194) dorsal aspect; (195) ventral aspect. LA, labium; MX, maxilla. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.10 mm.



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FIGURES 196–200. Rhantus validus (third-instar larva): (196) head capsule, dorsal aspect (not all secondary setae represented); (197–198) prothoracic leg; (197) anterior aspect; (198) posterior aspect; (199) abdominal segment eight, dorsal aspect; (200) urogomphus, dorsal aspect. Scale bars = 0.60 mm.


ALARIE ET AL.

FIGURES 201–205. Rhantus wallisi (first-instar larva): (201) head capsule, dorsal aspect (colour pattern not represented); (202–203) metathoracic leg; (202) anterior aspect; (203) posterior aspect; (204) abdominal segment eight, dorsal aspect; (205) urogomphus, dorsal aspect. AB, abdominal segment eight; CO, coxa; EB, egg bursters; FE, femur; FR, frontoclypeus; PA, parietale; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; filled squares refer to additional setae. Scale bars = 0.20 mm.



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FIGURES 206–210. Rhantus wallisi (third-instar larva): (206) head capsule, dorsal aspect (not all secondary setae represented); (207–208) prothoracic leg; (207) anterior aspect; (208) posterior aspect; (209) abdominal segment eight, dorsal aspect; (210) urogomphus, dorsal aspect. Scale bars = 0.50 mm.


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FIGURE 211. Strict consensus tree of 4800 most parsimonious trees reconstructed (43 informative characters of 35 taxa). Bremer support values are indicated above branches; jackknife values are indicated below branches.



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FIGURE 212. Strict consensus tree of 1400 most parsimonious trees reconstructed using implied weighting (43 informative characters of 35 taxa). Bremer support values are indicated above branches; jackknife values are indicated below branches.


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