Morphological variation and systematics of ... - Wiley Online Library

Mitt. Mus. Nat.kd. Berl., Dtsch. entomol. Z . 50 (2003) 1, 23-68

30.06.2003

Morphological variation and systematics of Canthon Hoffmansegg 1817, and related genera of new world Canthonini dung beetles (Coleoptera, Scarabaeinae) Claudia A. Medinal, Clarke H. Scholtz2 & Bruce D. Gill3 With 179 figures, 4 appendices and 1 table

Abstract Morphological variation was examined in 65 species of Canthon Hoffmansegg and 31 species in 11 additional genera of the tribe Canthonini (Anisocanthon Martinez & Pereira, Canthonella Chapin, Cryptocanthon Balthasar, Deltochilum Eschscholtz, Hansreia Halffter & Martinez, Holocanthon Martinez & Pereira, Malagoniella Martinez, Megathopa Eschscholtz, Melanocanthon Halffter, Scybalocanthon Martinez, and Sylvicanthon Halffter & Martinez). Morphological characters were examined on a total of 306 specimens. Variation in head structures such as clypeus, eyes, labium, gula, and epipharynx is described. Thoracic structures examined include pronotum, proepimeron, prosternum, and posterior and medial tibiae. Additional structures examined were the elytra, pygidium, and male genitalia, including the sclerites and brushes of the internal sac. Cladistic analysis of 39 taxa and 82 characters resulted in eight most parsimonious cladograms. The consensus tree confirms that Canthon is polyphyletic. Characters mainly from the epipharynx support the clade where most of the genera of Canthonini included in the analysis, with the exception of Cryptocanthon and Canthonella, are grouped. The species of the subgenus Francmonrosia form a clade supported mainly by synapomorphies from the internal male genitalia. Species of the genus Scybalocanthon share four synapomorphies with Canthon sordidus. Although there are some supported groups, there is extensive homoplasy in the cladogram mainly for characters of external morphology. A majority of the synapomorphies correspond to characters from the internal structures such the epipharynx and the internal male genitalia. Therefore we consider the internal morphology to be more informative in defining natural groups within Canthonini.

Key words: Coleoptera, Scarabaeinae, Canthonini, Canthon, Anisocanthon, Hansreia, Melanocanthon, Deltochilum, Malagoniella, Sylvicanthon, Scybalocanthon, Holocanthon, Cryptocanthon, Canthonella, morphological variation, internal male genitalia, cladistic analysis, systematics.

food materials (Halffter & Matthews 1966, Halffter & Edmonds 1982). Four tribes of roller beetles are currently reDung beetles of the subfamily Scarabaeinae have been the subject of several major ecologi- cognized (Canthonini, Scarabaeini, Gymnopleurical, behavioural and biogeographic studies ni, and Sisyphini). The tribe Canthonini is the (Halffter & Matthews 1966, Halffter & Edmonds largest and most complex tribe, with 93 genera 1982, Hanski & Cambefort 1991). Despite exten- and 803 described species (Hanski & Cambefort sive knowledge of the subfamily, phylogenetic 1991). Canthonini has a Gondwanian distribution studies are deficient. The current classification of with the largest number of genera and species in 12 tribes in the subfamily (Hanski & Cambefort the Americas (29 genera and 367 species). Many 1991), though widely followed, lacks phyloge- of the genera of Canthonini are monotypic (39), while others are numerous in species. Cunthon is netic support. Scarabaeine dung beetles have traditionally the largest genus with 174 currently described been separated into two functional groups or species, distributed from Argentina to Canada. guilds: the “tunnelers” and the “rollers”. The two More than 100 species of Cunthon are tropical, groups are recognized by their basic behaviour inhabiting forests or savannas. Species of Cunthon of either rolling or tunnelling, and by the general along with the genus Deltochilum represent 67% differences in external morphology associated of the American species in the tribe Canthonini with the activity of transporting dung or other (Halffter & Martinez 1966).

Introduction

Apartado Aereo 26 167, Cali Columbia, South America. Department of Zoology & Entomology, University of Pretoria, Pretoria 0002, Republic of South Africa. E-mail: [email protected], [email protected] Centre for Plant Quarantine Pests, Rm. 4125-960 Carling Avenue, Ottawa, Canada KlA OC6. E-mail: [email protected] Received November 2000, accepted November 2002

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are restricted to specific habitats such as inner forest, ecotones (forest borders), or savannas (Diaz 1997). Additionally, many species of Canthon are associated with dung of particular mammalian species, e.g., of monkeys (Gill 1991, Castellanos et al. 1999). Table 1 The genus Canthon was proposed in 1817 by Historical summary of the divisions of the genus Canthon Hoffmansegg, based on Ateuchus septemmaculatus Hoffmansegg 1817, since it was described. Generic names Latreille. Subsequently Harold (1868) described marked with an asterisk are currently considered as subgene47 species and provided a key for species identifira of Canthon (Halffter & Martinez 1977). cation. Between 1948 and 1966, Harold’s (1868) Year Author Genera (No. species) concept of Canthon was fragmented by different authors into 13 genera (Bates 1887, Martinez 1868 Harold Canthon (96) Pseudocanthon (1) 1887 Bates 1948,1952,1954, Pereira 1953, Pereira & Martinez Scybalocanthon ( 3 ) 1948 Martinez 1956,1959, Halffter 1958; Table 1). However, most Glaphyrocanthon *(17) of these new genera were subsequently reduced to Xenocanthon (1) 1952 Martinez Peltecanthon * (2) 1953 Pereira subgenera of Canthon by Halffter & Martinez 1954 Martinez Pseudepilissus * (2) (1977). In this monograph, nine subgenera and 1956 Pereira & Geocanthon (12) other subdivisions, such as groups and phyletic Martinez Goniocanthon * (2) Nesocanthon * (3) lines of Canthon were proposed (Table 1). This 1958 Halffter Boreocanthon * (14) work, however, does not provide detailed diagMelanocanthon (4) noses of these species groups, and the taxonomy 1959 Pereira & Canthomoechus (1) Martinez Francmonrosia * (2) of the groups is still imprecise. Trichocanthon * (1) The taxonomic history of Canthon reveals im1977 Halffter & Canthon Hoffmansegg portant difficulties in the definition of the genus Subgenus Canthon Hoffmansegg Martinez Line aberrans (1) and in the delimitation of the groups of species Line coeruleicollis (2) related to it. The diagnostic characters used for Line chiriguano (20) many of the American genera of Canthonini, inLine delpontei (1) Line daguerrei (1) cluding Canthon, occur in various combinations Line humectus (6) of states, indicating significant character conflict. Line angularis ( 2 ) Line substriatus (2) The lack of appropriate morphological studies Line pilularius (4) and phylogenetic analyses in these groups is the Line obliquus (1) main reason for unclear limits among them. Line indigaceus (3) The objective of the present study is to docuLine deyrollei (1) Line lituratus (2) ment the variation of different morphological Line bispinus (1) structures among the subgenera of Canthon and Group virens (6) Group lividus (3) to compare this variation with that of other Group cinctellus (9) American genera of Canthonini (i.e., AnisocanGroup cyanellus (3) thon, Canthonella, Cryptocanthon, Deltochilum, Group quadripunctatus (2) Line janthinus (5) Hansreia, Holocanthon, Malagoniella, MelanoLine aequinoctialis (1) canthon, Scybalocanthon, and Sylvicanthon). We Line juvencus ( 5 ) sought to determine the relative utility of exterSubgenus Boreocanthon Halffter (15) nal morphological characters or characters of inSubgenus Francmonrosia Pereira & Martinez (10) ternal structures such as the epipharynx and the Subgenus Glaphyrocanthon Martinez (42) internal male genitalia in elucidating phylogeSubgenus Goniocanthon Pereira & Martinez ( 2 ) netic relations within Canthon.

Dung beetles have been proposed as useful tools for monitoring biodiversity and for designating areas for conservation priority (Favila & Halffter 1997). Many species of Canthonini, including those of Canthon, are stenotopic: they

Subgenus Nesocanthon Pereira & Martinez (3) Subgenus Peltecanthon Pereira (3) Subgenus Pseudepilissus Martinez (7) Subgenus Trichocanthon Pereira & Martinez (1) Incertae sedis (7) Line septemmaculatus Group septemmaculatus (10) Group maldonadoi ( 5 ) Line quinquemaculatus (1) Line quadratus (3)

Methodology Specimen preparation Dry specimens were softened by immersion in hot water for 30-60min, depending on specimen size. The mouthparts and male genitalia

Mitt. Mus. Nat.kd. Berl., Dtsch. entomol. Z . 50 (2003) 1

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were removed, cleaned in hot water solution of KOH, and studied on microscope slides with glycerol.

nious cladograms were found using the commands ‘hold lOOO’, ‘mult” lOOO’, and ‘max*’ in the program Nona (Goloboff 1995). Character state distributions were examined using the program Clados (Nixon 1995) and Winclada (Nixon Character examination 1999). Branch support values (Bremer 1994) A total of 306 specimens of 96 species was exam- were calculated to examine character support ined, including 65 species of Canthon and 30 spe- throughout the cladogram. Support values were cies of other genera of Canthonini (Appendix 1). calculated using Nona by reading in the consenApproximately 40% of the described species sus of the most parsimonious cladogram and of Canthon were examined. Although we in- using commands ‘hold 60000’ ‘sub-optimal 9’ and cluded species from all recognized subgenera of ‘bsupport 9’. The results were saved to an output Canthon, a limitation of this work is that it does file for posterior viewing. not include all the species in the genus. The descriptions in this study refer only to those species General appearance (Figs 1-4) listed in Appendix 1. Occasionally, reference is made to other species that were studied in the The dorsal appearance of Canthon is smooth, collections visited or cited from descriptions in and most species have a flat head and reduced eyes. The lack of horns, tubercles or other prothe literature. jections on the dorsal surface of Canthon results The following individuals and institutions proin a simple external morphology (Fig. 1). Howvided the material studied: ever, much variation in the external morphology ALIC Alejandro Lopera, private collection, Santaf6 de Bowas observed among the species of Canthon exgota, Colombia. BDGC Bruce D. Gill, private collection, Ottawa, Canada. amined. Variation in the shape of the clypeus, CMNC Canadian Museum of Nature, Aylmer, Canada. sculpturing and colouration of elytra is noticeCNCI Canadian National Collection of Insects, Ottawa, ably large within Canthon. The excavation of the Canada. FGPC FranGois GCnier, private collection, Aylmer, Canada. proepimeron and the variation of the proepisterFVMC Fernando Vaz de Mello, private collection, Lavras, nal keel are highly variable among the species. Brazil. Canthon is composed of a group of beetles of IAVH Instituto Alexander von Humboldt, Villa de Leyva, Colombia. variable colour and size, ranging from 3 mm to NHML Natural History Museum, London, UK. 22mm in length. Many species are dark-coSAMN South Australian Museum, North Terrace, Adelaide, Australia. URCM Universidad de La Republica, Montevideo, Uruguay. URCA Universidad de Rio Cuarto, Rio Cuarto, Argentina. PUJC Pontificia Universidad Javeriana, Santaf6 de Bogotd, Colombia.

Cladistic analysis As no previous systematic study exists for Canthon and its phylogenetic relationships were unknown, different genera of Canthonini were used for outgroup comparisons. Representatives of each of the nine subgenera of Canthon, for a total of 27 species, were included in the analysis. Also included were three species of the genus Scybalocanthon and one species of each of the following genera: Canthonella, Cryptocanthon, Deltochilum, Malagoniella, Megathopa, Hansreia, Melanocanthon, Sylvicanthon, and Anisocanthon, for a total of 39 taxa (Appendix 2). Eighty-three morphological characters were used for the cladistic analysis. Sixty-one binary and 22 multistate characters were coded (Appendix 3). The characters were run as unordered. The most parsimo-

Fig. 1. Habitus: Canthon luteicollis Erichson.

Medina. C. A.. C. H. Scholtz & B. D. Gill. Momholoeical variation and svstematics of Canthon (Scarabaeinae)

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loured (opaque or glossy) whereas some are green, bronze, or black with a bronze sheen. Others are brightly coloured on the surface, generally combined with a dark colour. Many species of Canthon have light-coloured pronota, often yellow or brown with dark spots or maculations. Some species also have light-coloured femora and tibiae and light-coloured maculations on the pygidia. One important consideration is that many species of Canthon exhibit large variation in colouration among individuals of the same species from different geographical regions. The species Canthon quinquemaculatus is widely distributed, from Peru to Argentina, and can vary from completely dark to a combination of dark elytra with reddish pronotum and pygidium, or brownish elytra with dark maculations on the pronotum. In many others species (e.g., C. septemmaculatus, C. cyanellus, C. pilularius, C. aberrans) the colour variation is pronounced (Figs 2-4). This intra-specific colouration has been used for some authors to designate subspecies; for example differences in subspecies of C. rutilans and C. latipes (Pereira & Martinez 1959). The thorax is very convex and smooth, and the elytra are generally smooth, although some species have tubercles in the humeral area and small tubercles at the base of the elytral grooves. The pygidium is typically large and not covered by the elytra. Species of Canthon show sexual dimorphism in the shape of the anterior tibia1 spur, and the shape of the last abdominal sternite.

Figs 2-4. Pronotum dorsal view. 2. C. septemmaculatus septemmaculatus (Latreille). 3. C. septemmaculatus histrio (Serville). 4. C. cyanellus sallei Harold. Scale bar = 2 mm.

Figs 5-6. 5. Dorsal view of the head of Canthon angustatus Harold. 6. Ventral view of the head of C. fulgidus (Redtenbacher). ca = canthus, cl = clypeus, cls = clypeal suture, ey = eye, an = antennae, mn = mentun, gl = gula, gn = gena. Scale bar = 1mm.


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Figs 7-12. Anterior clypeal margins, dorsal view. 7. Canthon chalcites (Haldemann). 8.C. lunatus tibialis Schmidt. 9. C. aequinoctialis Harold. 10.C. monilifer Blanchard. 11.C. bicolor Laporte. 12.C. fulgidus (Redtenbacher). cls = clypeal suture, gn = gena. Figs 7, 9, 10, 11 scale bar = 2 mm. Figs 8 and 12 scale bar = 1mm.

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plane. The mouthparts are positioned ventrally and directed anteriorly. The head capsule is fully The head of Canthon is typically prognathous, sclerotized and darkly coloured in most species. with the main axis oriented on a horizontal Its dorsal surface is generally flat and smooth,

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Figs 13-19. Anterior clypeal margins, dorsal view. 13. Canthon femoralis (Chevrolat). 14.C. luteicollis Erichson. 15.C. quinquemaculatus Laporte. 16.C. ebenus (Say). 17.Melanocanthon bispinatus (Robinson). 18.Malagoniella astyanax (Blanchard). 19. Deltochilum gibbosum (Fabricius). CIS = clypeal suture, clse = clypeal setae, gn = gena. Fig. 13 scale bar = 1mm, Figs 14-19 scale bar = 2mm.


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I Figs20-26. Ventral view of the clypeus 20. Canthon fulgidus (Redtenbacher). 21. C. fernoralis (Chevrolat). 22. Hansreia affinis (Fabricius). 23. Malagoniella astyanax (Blanchard). 24. C. praticola LeConte. 25. Melanocanthon bispinatus (Robinson). 26. Anisocanthon villosus (Harold). Scale bar = 1mm.

without tubercles, horns, or raised carinae. The head is bordered anteriorly by the clypeus, which is often medially emarginate, forming clypeal teeth. The exposed dorsal surface of the eye is normally much reduced in size compared to the ventral portion, and is bordered laterally by an ocular canthus (Fig. 5 ) . The gula, mentum, and labium are exposed in ventral view (Fig. 6), and cover the maxillae, mandibles and epipharynx. A pair of nine-segmented antennae is inserted ventrally in the head capsule near the lower portion of the eye. The antenna1 club is composed of the last three antennomeres (Fig. 6). Clypeus dorsally (Figs 7-19) In Canthon there is a wide range of variation in the anterior border of the clypeus; from slightly

sinuate to a completely divided clypeus; with two or four well-marked teeth. The sinuate clypeus is present in species of the subgenus Canthon, (pilularius group: C. chalcites, c . imitator, and C. pilularius; and in C. lunatus tibialis; Figs7-8). Among species with well-developed teeth on the clypeus, there is great variation even among species of the same subgenus where two or four clypeal teeth can be seen (e.g. Glaphyrocanthon, and Francmonrosia). Many species of Canthon have two well-defined teeth on the clypeus. Depending on their size and shape, these teeth may form a sharp “V” or a broadly rounded “U” in the middle of the clypeus. The most common pattern is the presence of two triangular, blunt teeth (e.g., C. aequinoctialis, C. bicolor, C. luteicollis, C. indigaceus, C. tetraodon, C.fulgidus, C. deyrollei, and C. sub-


hyalinus and C. perseverans; Figs 9-12). In some species of the subgenus Glaphyrocanthon (C. angustatus, C. femoralis femoralis, and C. femoralis bimaculatus), the teeth of the clypeus form a deep “V” and laterally there is a wide notch, which makes the clypeus appear as if it had another pair of teeth (Fig. 13). Others species like C. tetraodon and C. deyrollei show a similar notch, but the teeth are blunt rather than sharp. In species that have four teeth, different patterns were observed. Some species have very long and sharp central teeth forming a deep “V” such as C. cyanellus and C. quinquemaculatus (Fig. 15). Others species have four teeth, but the two central teeth form an arcuate depression and not a deep “V” (i.e., C. acutus). The gena can be complete or divided by the clypeogenal suture. In species of the subgenus Boreocanthon and the genus Melanocanthon, the

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clypeogenal suture divides the gena, which makes it appear as if they have another pair of teeth on the sides of the clypeus (Figs 16-17). The gena can have a notch at the level of the clypeogenal suture. This notch can be wide (e.g., C. quinquemaculatus, C. cyanellus, C. deyrollei, C. indigaceus, and C. bicolor), or narrow (e.g., C. luteicollis, C. septemmaculatus, C. staigi, C. sordidus, and C. triangularis; Figs 14, 17). A complete gena (without a notch) is present in C.fulgidus and in some species of the subgenus Glaphyrocanthon (C. femoralis, C. angustatus) and in species of the subgenus Canthon (i.e., indigaceus and humectus lines; Figs 13,18). The gena is also complete in species of the genera Scybalocanthon, Sylvicanthon, Canthonella, Cryptocanthon, and Deltochilum (Fig. 19). The portion between the clypeogenal suture and the anterior margin of the clypeus can be rounded, as in most species of Can-

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Figs 27-33. Dorsal view of the eyes. 27. Canthon bicolor Laporte. 28. C. politus Harold. 29. Hansreia aflnis (Fabricius). Figs 30-33 Dorso-lateral view of the eye. 30. C. deyrollei Harold. 31. C. lecontei Harold. 32. C. indigaceus LeConte. 33. Sylvicanthon bridarollii (Martinez). ca = canthus, ey = eye. Arrows showing the carinate margin of the ocular canthus. Figs 27-29 scale bar = 2 mm, Figs 30-33 scale bar =1 mm.

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thon, or straight (e.g., C. luteicollis, C. angustatus, C. cyanellus, C. tetraodon, C. deyrollei, C. maldonadoi, C. indigaceus, and C. humectus; Fig. 5). The anterior margin of the clypeus can possess setae or be completely glabrous. The setae are generally arranged in a row at the base of the clypeal teeth. In species of the subgenus Boreocanthon and the genus Melanocanthon, this row extends towards the sides of the genae, whereas in other species this row is in the centre of the clypeus, typically at the base of the teeth (Figs13, 14). In C. maldonadoi, these setae are as long as the teeth. In C. fulgidus, C. quinquemaculatus, C. bicolor, and C. staigi, the setae do not form a row but are clumped in a pair of bundles at the base of the teeth (Figs 11, 12, 129). In Malagoniella astyanax, the setae are conspicuous at the base of the teeth (Fig. 18).

Clypeus ventrally (Figs 20-26) Ventrally, the clypeus shows great variation within Canthon. On the ventral side of the clypeal teeth there is a U-shaped structure, delineated by conspicuous punctures and long thick setae (Fig. 20, 23). This structure is present in most of the Canthon subgenera with the exception of the subgenus Boreocanthon, and is present in other genera such as Malagoniella, Anisocanthon, Hansreia, Scybalocanthon, and Sylvicanthon (Figs 24-26). It is also present in some species of other Scarabaeinae tribes such as the Phanaeini (Edmonds 1972). Behind the teeth, between the base of the teeth and the anterior margin of the epipharyngeal cavity, there is generally smooth area in most Canthon species. However, in C. fernoralis, C. luteicollis and C. tetraodon a longitudinal central carina and a few small lateral protuberances were observed (Fig. 21). This longitudinal carina is also present in Hansreia affinis, Malagoniella astyanax, and Sylvicanthon bridarollii (Figs 22, 23). This area is generally covered by setae, but C. fulgidus, C. chalcites, C. bicolor, C. praticola, C. simplex, and C. staigi have the area behind the base of the clypeal teeth completely glabrous. In other species of Canthonini this area is mostly glabrous, except in A. villosus, S. pygidialis, and S. bridarollii (Fig. 26). In species of the subgenus Boreocanthon there is a sharp margin at the base of the clypeal teeth and the area posterior to the teeth is generally reduced in relation to other species of Canthon (Fig.24). In the genus Melanocanthon, a longitudinal keel and a well-developed tooth is present at the base of the clypeus (Fig. 25).

Eyes (Figs 27-33) In dorsal view, the eyes of most species of Canthon are narrow (Fig. 28). A projection of the integument of the head rests over the eye surface (forming the canthus) and gives the eye a long and narrow appearance. However, some species of Canthon (e.g., C. aequinoctialis, C. perseverans, and C. bicolor) have dorsally wide eyes, as do species of the genera Sylvicanthon and Canthonella (Figs 27, 33). Other genera of Canthonini, such as Melanocanthon, Scybalocanthon, Anisocanthon, and Hansreia have dorsally narrow eyes as in most species of Canthon (Fig. 29). In many species of Canthon the posterior part of the eye is narrower than the medial part of the eye (Fig. 30). This kind of eye is present in species of the subgenera Glaphyrocanthon and Canthon, in contrast to C. pilularius, C. bicolor, C. staigi, C. perseverans, and species of the subgenus Boreocanthon, which have a wide posterior opening of the eye. In other genera, such as Canthonella, Deltochilum, Malagoniella, Sylvicanthon, and Melanocanthon, the posterior part of the eye is wide, whereas Scybalocanthon, Anisocanthon, and Hansreia have posteriorly narrow eyes similar to most Canthon (Fig. 33). In species of Canthon the eyes are bordered laterally by a flattened ocular canthus. In some groups of species the margin of the canthus adjacent to the eye can be carinate (thickened and

Fig. 34. Generalized epipharynx of Canthon. mp = medial process, af = apical fringe, Ic = lateral combs, tm = tormal process, ts = transverse suture.

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Figs 35-38. Epipharynx. 35. Detail of posterior area of medial process of epipharynx, Cunthon polifus Harold. 36. Lateral comb of Cunthonellu gomezi (Halffter & Martinez). 37. Ventral view of the epipharynx of C. ucutus Harold; arrow indicates the transverse suture. 38. Detail of different kinds of setae covering the epipharynx of C. chalcifes (Haldemann). Setae on the extreme right of the image correspond to the central area of the epipharynx, those in the middle correspond to setae of the first lateral comb, and those on the extreme left correspond to the second lateral comb of the epipharynx. Magnification =

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elevated). Species of the subgenera Boreocunthon and Canthon (i.e., C. aberrans, C. chiriguano, C. humectus, C. indigaceus and C. deyrollei), as well as C. tetraodon and C. lunatus tibiulis, have a carinated ocular canthus surrounding the eye. In C. deyrollei and C. indigaceus, the carinated portion of the ocular canthus is conspicuously broad (Figs 30-32). Epipharynx (Figs 34-50) The epipharynx is oriented horizontally, and located above the ventral side of the clypeus, under the mandibles and maxillae. It is a hollow structure formed by a double membrane thickened in its central portion. In the upper mem-

brane, a transverse suture joins the epipharynx to the clypeus. This suture crosses the epipharynx at the medial part, and is known as the labro-clypeal suture (Nel & Scholtz 1990), or the labro-clypeal sulcus (Edmonds 1972). The ventral membrane is covered by numerous thick and thin setae. The thickest setae are located in the central region and clumped in the medial process of the epipharynx (Figs 34, 37). The medial process of the epipharynx is a slightly sclerotized, anterior enlarged structure that crosses the epipharynx longitudinally. This structure is known as the antero-medial process, which is formed by the median brush (Edmonds 1972), or “vhstago claviforme” (Halffter 1961). Anteriorly, the medial process is club-shaped and

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Figs 39-42. Detail of the lateral combs of the epipharynx. 39, 40. Cunthon ebenus (Say). 41. C. Zunutus tibiulis Schmidt. 42. C. bicolor Laporte. Figs b, c, and d magnification = 20 x, Fig. a magnification = 40 x.

is covered by abundant setae. Toward the medial and posterior portions, the medial process is thin, free of setae and ends in an inverted coneshaped structure, with a row of hook-shaped hairs, usually curved forward and downward (Figs 47-50). In species of Canthon, the medial process varies in shape, and in the number and arrangement of setae. The central region of the epipharynx (lateral to the medial process) has thick setae, each with a small fovea at its base (Fig. 38). These setae are usually thin, erect, curved downward at their apex, and show variation in their number and arrangement in the central region. Among the thick setae there are other kinds of setae, mostly smaller ones or very small and

silky ones that cover the central area. To the sides of the central region, are the lateral combs, formed by longitudinal bands of setae (Fig.34). In species of Canthon, two well-defined lateral combs are observed. The first lateral comb (nearest to the medial process) is formed by a longitudinal row of thick setae with their ends pointing toward the central region. The setae gradually decrease in size from the anterior part of the epipharynx to the posterior end of the comb, approximately on the posterior portion of the medial process (Fig. 41). In general, the last setae of the first comb differ in size and thickness from the setae of the second comb, which are thinner and shorter. The second comb is not formed by a single row of setae, but is a wide

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Figs 43-46. Detail of the anterior area of the medial process of the epipharynx. 43. Canthon stuigi (Pereira); arrow indicates the space between the medial process and the anterior border of the epipharynx. 44. C. tetraodon Blanchard. 45. C. lunatus tibiulis Schmidt. 46. C. ebenus (Say). Magnification 20 x.

band of short and thin setae interwoven without forming well- defined rows (Figs 39-41). The base of the epipharynx or proximal epipharynx (Nel & Scholtz 1990), is a slightly more sclerotized area that forms a plate with two more or less circular hollows in the medial area, and one central and two lateral chitinous projections (Fig. 34). The lateral projections, called tormae (Snodgrass 1935), or tormal process of labral suspensorium (Edmonds 1972, Nel & Scholtz 1990), are connected with the sclerites, in which the muscles that move the epipharynx are inserted. The epipharynx has been poorly studied in genera of Canthonini, despite the fact that Halffter (1961) mentioned its taxonomic value in his monograph of North America Canthon. This lat-

ter author noticed clinal variation in the number of setae of the lateral combs in different populations of Canthon vigilans. The epipharynx of most species of Canthon is quadrangular, with the medial process well developed and covered by abundant setae. It differs from other genera of Scarabaeinae, by having two well-defined lateral combs. In other groups of Scarabaeinae such as species in the tribes Phanaeini (Oxysternon conspicillatum (Weber) and Phanaeus pyrois Bates) and Ateuchini (Dichotomius satanas (Harold)), only one defined comb is observed (C. A. Medina personal observations). The general pattern observed in Canthon is the presence of a narrow strip free of setae between the two lateral combs. This strip is evident

34

Medina, C. A., C. H. Scholtz & B. D. Gill, Morphological variation and svstematics of Canthon (Scarabaeinae)

47

4%

49

50

Figs47-50. Detail of the posterior region of the medial process of the epipharynx. 47. Canthon lunatus tibialis Schmidt. 48. C. acutus Harold. 49. C. cyanellus sallei Harold. 50. C. bicolor Laporte. Figs 47, 49 and 50 magnification 20 x, Fig. 48 magnification 40 x.

on the anterior half of the epipharynx and be- and thickness from the setae in the second comb. comes somewhat narrower on the posterior half. In species of Deltochilum and in Malagoniella asIn a few species of Canthon the fringe is lost due tyanax, the second lateral comb fuses with the to the posterior fusion of the combs, usually at first comb from the posterior half of the egithe transverse suture in which the combs are pharynx, more or less at the level of the transfused (i.e., C. bicolor, C. staigi, C. smaragdulus, verse suture, forming a broad fringe of hairs, in and C. cyanellus), it was possible to identify the which the combs are no longer recognisable. In first comb because its setae were larger than genera such as Cryptocanthon and Canthonella those in the second comb. Canthon bicolor and the first comb is not complete; it only runs over C. staigi were the only two species in which the the anterior third of the epipharynx (Fig. 36). In combs fuse before the transverse suture (Fig. 42); Scybalocanthon, Sylvicanthon, and Hansreia, the in C. cyanellus and C. filgidus the combs fuse at first comb is well differentiated on the anterior the level of the transverse suture. In the other part, but it fuses with the second comb just after genera of Canthonini studied, the setae of the the transverse suture. In Anisocanthon and Melafirst comb are not as thick and long as those in nocanthon, the lateral combs of the epipharynx the first comb of Canthon, and gradually become are well defined and are not different from the smaller until they cannot be differentiated in size lateral combs of Canthon.


35

52

I

Within Canthon, the medial process shows great variation in the shape of the anterior end, which can be enlarged and rounded anteriorly, or end in a point (Figs 43-46). In species of the pilularius group of the subgenus Canthon, the subgenus Boreocanthon, and in some species of the subgenus Glaphyrocanthon, the medial process is pointed (Fig. 44). In the rest of the species examined, the medial process does not end in a point, but is rounded (Figs 43, 46). There is also variation within Canthon in the general shape of the medial process, but we did not observe a clear pattern within subgenera or species groups. Furthermore intra-specific variation in the shape of the medial process has been observed in some species of Canthon (Halffter 1961). In most of the species studied, the medial process ends over the anterior margin of the epipharynx. In c . staigi and c. bicolor there is a space between the medial process and the anterior margin of the epipharynx (Fig. 43). The posterior end of the medial process also shows great variation. In general, the medial

Figs51-54. Dorsal view of labium. 51. Canthonella gomezi (Halffter & Martinez). 52. Canthon pallidus Schmidt. 53. C. ebenus (Say). 54. C. tetraodon Blanchard. Scale bar = 0.5 mm.

process ends in a conical structure that varies widely in size and shape, and is usually fringed by a single row of hairs, which in some species are curved forward and downward, and in other species are less curved (Figs 35, 48). In some species there is not a well-defined row of hairs but rather a clump of hairs such as in C. bicolor, or a double row of hairs such as in C. acutus or C. lunatus tibialis (Figs 47-50). Due to the difficulty in distinguishing these hairs, their variation was not studied in detail in all the species. The anterior margin of the epipharynx is covered by a row of setae, referred to by Edmonds (1972) as the apical fringe, which is present in most families of Scarabaeoidea (Nel & Scholtz 1990). Within Canthon, the hairs of the apical fringe are long and thin, in contrast with species of the other genera of Canthonini, which have short and thick hairs such as in Canthonella, Cryptocanthon, and Deltochilurn. In most of the species of Canthon these long hairs are present, except in species of the subgenera Boreocanthon and Pseudepilissus (Figs 45, 46). The lateral ends

36

Medina. C. A.. C. H. Scholtz & B. D. Gill, Morphological variation and systematics of Canthon (Scarabaeinae)

In Canthonella, Cryptocanthon and Hansreia, the anterior border of the mentum is complete (Fig. 51), whereas in Scybalocanthon, Sylvicanthon, Malagoniella, and Deltochilurn it is sinua te as in Canthon. A completely divided mentum is present in the genus Holucanthon. In general, beetles have a well-developed gula, Labium and gula (Figs 51-61) a characteristic associated with the general progThe labium is a ventral lobe, anterior to the gula, nathous condition. The gula is separated from fused with the mentum and submenturn. The most the submentum by a well-marked transverse suevident variation is present on the anterior border ture. In most Scarabaeidae this separation is not of the mentum, which can be complete, sinuate or evident; instead a row of setae is present that completely divided. Canthon usually has a sinuate could be homologous to the suture that sepamentum; slightly so in some species such as C. an- rates the gula from the submentum, as in the gustatus, C. politus, C. fulgidus, C. pallidus, and Melolonthine genus Phyllophaga (Edmonds species of the viridis group (Fig. 52), and deeply 1972). In Canthon and other Scarabaeinae this sinuate in species of the subgenera Boreocanthon, row of setae has modifications and is not a true Francmonrosia, species of the pilularius group, separation between these two areas. In Canthon and others of the subgenus Canthon (Figs 53,54). this section of the gula is recognised by having a

of the anterior margin of the epipharynx are covered by long and thick hairs, which are slightly curved towards the center. The abundance of these hairs varies among species, but we did not observe a clear pattern.

Figs 55-61. Dorsal view of the gula and mentum. 55. Canthon angustutus Harold. 56. Canthonella gornezi (Halffter & Martinez). 57. C.humectus (Say). 58. C. pruticolu LeConte. 59. C. chulcites (Haldemann). 60. Hunsreia ufinis (Fabricius). 61. C. violuceus (Olivier). Fig. 55 scale bar = 0.5 mm, Figs 56-61 scale bar = 1mm.


37

Figs62-68. Dorsal view of pronotum. 62. Cantkon septemmaculatus septemmaculatus (Latreille). 63-68 Lateral margin of pronotum. 63. c. bicolor Laporte. 64. C. aequinoctialis Harold. 65. C. femoralis (Chevrolat). 66. C. angustatus Harold. 67. C. deyrollei Harold. 68. C. juvencus Harold. Scale bar = 1mm.

Fig. 69. Generalized ventral view of first segment of the thorax of Cantkon. cc = coxal cavity, ep = proepimeron, pr = proepisternum, pe = prosternum pek = proepisternal keel. Scale bar = 1mm.

different sculpture, not smooth (as the rest of the surface of the gula) and being covered by setae. Within Canthon there is much variation in the shape of this area, and in the abundance and length of the setae, but this variation is not exclusive to the genus. Most of the variation is in the shape of this area and in the abundance of the setae that cover it. Some species have a groove with a row of setae that runs transversally over the gula, as in some species of the subgenus Glaphyrocanthon. Outside of Canthon this row of setae is present in Canthonella gomezi and Cryptocanthon. The row of setae becomes thicker, with more setae, and in some species it

38

Medina. C. A.. C. H. Scholtz & B. D. Gill. Morphological variation and systematics of Canthon (Scarabaeinae)

is curved as in the subgenus Pseudepilissus, species of the subgenera Canthon, Glaphyrocanthon and in C. quinquemaculatus and C. septemmaculatus. Other species have a triangular area with a different sculpture, marked with punctures and thick setae. Species of the subgenus Boreocanthon, the pilularius group, and other species of Canthon, as well as the genera Anisocanthon, Hansreia, Scybalocanthon, Sylvicanthon, Deltochilum, Malagoniella, and Melanocanthon have this triangular area (Figs 55-61). In some species of Canthon (e.g., c. fulgidus, c. staigi, c. bicolor, and C. violaceus), and in species of Deltochilum the setae of this area are noticeably long.

75

Thorax (Figs 2-4, 62-68) The pronotum in the Scarabaeidae is well-developed, transversally expanded, and usually wider than long. In species of Canthon the pronotum is usually smooth, glossy and very convex, without tubercles or protuberances (Figs 2-4, 62). Although in other groups of Scarabaeinae, including some genera of Canthonini, the scutellum is visible at the base of the elytra, in Canthon this segment is reduced, and only in species of the subgenus Peltecanthon is the apex visible between the bases of the elytra (Halffter & Martinez 1977). In descriptions of the species of Canthon it is common to use the shape of the lateral margin of the pronotum, as well as the shape of the anterior and posterior angles. However, a precise

-----J

Figs 70-75. Proepisternum and proepimeron view. 70. Cunthon politus Harold. 71 C. humectus (Say). 72. C. morsei Howden. 73. Sylvicanthon bridarollii (Martinez). 74. C. pallidus Schmidt. 75. C. angustatus Harold. Scale bar = 1 mm.


pattern in the shape of the pronotum among the groups was not discerned. An example of the variation of this structure can be appreciated in the Figs (63-68). Proepisternum and proepimeron (Figs 69-86) In Canthon and other genera of Canthonini, the proepisternum can be deeply excavated and limited posteriorly by a keel (the proepisternal keel; Fig. 69), or it can be not excavated, in which case the proepisternal keel is usually absent, but if it is present then it does not reach the lateral border of the pronotum. In general, species that have a deeply excavated proepisternum also have a complete proepisternal keel. These two features were used by

39

Martinez (1948) in the description of the genus Glaphyrocanthon. However, neither an excavated proepisternum nor a complete proepisternal keel is exclusive to the subgenus Glaphyrocanthon. Species of subgenus Canthon and other genera such as Anisocanthon, Canthonella, Cryptocanthon, and Sylvicanthon also have an excavated proepisternum and a complete proepisternal keel (Figs 70-73, 75). Different genera of Canthonini such Deltochilum, Malagoniella, Megathopa, and Scybalocanthon, among others, do not have an excavated proepimeron or a proepisternal keel either (Figs 84-86). These latter two features are also present in many groups of species of Canthon, although some species have an incomplete proepisternal keel. There is a wide range of variation in

76

78

80

Figs 76-81. Proepisternum and proepimeron view. 76. Canthon brunneus Schmidt. 77. C. deyrollei Harold. 78. C. staigi (Pereira). 79. Hunsreia ufinis (Fabricius). 80. C. cyanellus sallei Harold. 81. C. ebenus (Say). Scale bar = 1mm.


40

the proepisternal keel: 1) an incomplete proepisternal keel, that overlaps at least half of the proepisternal area (subgenera Glaphyrocanthon, Canthon, and the genus Hansreia; Figs 74, 78, 79), 2) a short proepisternal keel located at the base of the coxae and overlapping less than half of the proepisternal area (subgenus Boreocanthon, C. lunatus tibialis, C. cyanellus, C. bicolor, C. tetraodon, C. quinquemaculatus, and the genus Holocanthon; Figs 76, 80-82) and 3) a faintly indicated keel, that runs near the anterior border of the proepisternum (subgenus Trichocanthon; Fig. 83). In Canthon the proepisternum has long setae. This feature was observed in all the species of Canthon examined, except C. humectus. The

v

82

other genera of Canthonini, except for Cnnthonella, Cryptocanthon, Scybalocanthon, and Sylvicanthon, also showed setae on the proepisternum. There is variation in the abundance and size of the proepisternal setae. Most of the species of Canthon have long and abundant setae (more than 12); only C. cyanellus, C. triangularis, and C. bicolor have a few, short setae. The proepimeron, is either setose or glabrous. Species of Boreocanthon have setae on the proepimeron, although their abundance and size varies among species. Abundant and long setae are present in C. simplex and C. ebenus, whereas in C. praticola few and short setae are present. In species of several subgenera of Canthon the presence/absence, abundance and size of the setae

03

I ' 85 84

Jh

86

T

Figs 82-86. Proepisternum and proepimeron view. 82. Canthon lunutus tibialis Schmidt. 83. C. sordidus Harold. 84. C. septemmaculutus (Latreille). 85. Deltochilum gibbosum (Fabricius). 86. C. violaceus (Olivier). Figs 83, 84, 86 scale bar = 1mm, Fig. 82 scale bar = 0.5 mm, Fig. 85 scale bar == 3 mm.

41


on the proepimeron vary without a clear pattern. However, in the species examined of the subgenus Glaphyrocanthon, the proepimeron is glabrous. One of the characters traditionally used to separate the genus Megathopa from Malagoniella is the presence of a fine keel on the epipleura and proepimeron (Martinez 1961). This keel is parallel to the lateral border of the pronotum and is usually accompanied by setae and punctures (Halffter & Martinez 1977). In species of the genus Malagoniella the keel is not present, but several setae overlap the proepisternum and the proepimeron, without reaching the posterior border of the pronotum (Martinez 1950). In the species of Canthon and other Canthonini examined, we observed great variation in this row of setae and punctures. In the species examined, a welldefined keel was not observed. In some species only a row of setae was observed and, in others, a row of setae and punctures was observed. The row of setae can overlap both the proepisternum and the proepimeron, as in several species of Canthon (e.g., C. cyanellus, C. maldonadoi, and C. violaceus;Fig. 82).

87

88

Mesosternum (Figs 87-90)

89

v

The mesosternum is located ventrally and posterior to the prosternum, over the medial coxae. It is a very narrow and reduced transverse sclerite present in some species of Canthon. Although the width of the mesosternum has taxonomic value, and has been used in the descriptions of species of Canthon, it is difficult to discern a pattern among the subgenera. Although it is usually reduced in species of Canthon, in some species the mesosternum can be wider, as in C. obliquus (Halffter 1961). The genera Sylvicanthon, Hansreia, and Scybalocanthon have the mesosternum reduced as in Canthon, in contrast to other genera of Canthonini such as Pseudocanthon Bates, Canthonella, and Cryptocanthon, which have a broad mesosternum (Figs 87-90). Legs

90 Figs 87-90. Mesosternum view. 87. Canthon fulgidus (Redtenbacher). 88. C. luteicollis Erichson. 89. Pseudocanthon sp. 90. Sylvicanthon bridarollii (Martinez). Scale bar = 2 mm.

Fore legs (Figs 91-102) The forelegs are short and flattened. The femur is usually rounded and thick basally and narrowed distally. Species of the subgenera Francrnonrosia have the ventral side of the femur excavated, and a prominent tooth on the anterior margin (Figs 91, 92). The ventral side of the fe-

42

91

Medina. C. A.. C. H. Scholtz & B. D. Gill, Moruhological variation and systematics of Canthon (Scarabaeinae)

1

92

mur has a well-marked anterior margin, and in C. filgidus (subgenus Goniocanthon) the margin forms a keel. In none of the Peruvian specimens of this species examined did we observe a wellmarked tooth as mentioned by Pereira & Martinez (1956) and Halffter (1961) for Brazilian specimens. The variation of the femur in species of Canthon is mainly in the form and sculpture, but no discernible pattern was observed. The tibia is dorsally flattened, distally broad, and is overlapped by two longitudinal keels dorsally as well as ventrally. These keels are generally parallel to the lateral margin of the tibia, but the pattern they follow varies among species. The dorsal keels are covered by long and thick setae, whereas the ventral keels are covered by short spines. The outer lateral margin of the tibia is serrated with small teeth, and in the medial and distal part there are three well-developed triangular teeth. In some species the third tooth is very reduced, and in the males of C. angustatus it is absent. These teeth vary in position and orientation. In many species of Canthon the teeth occupy the distal half of the tibia, as in the subgenera Boreocanthon and Canthon. In the subgenus Glaphyrocanthon (except C. angustatus), C. tetraodon, C. staigi, and C. perseverans, the teeth also occupy most of the distal half of the tibia (Figs 93, 94, 95). Outside of Canthon this pattern is present in the genus Malagoniella and in species of the genus Melanocanthon. In other species the teeth are located on the distal third of the tibia, as in C. aequinoctialis, C. bicolor, C. cyanellus, C. fulgidus, C. quinquemaculatus, C. triangularis, and C. septemmaculatus (Figs 95, 96). The other genera of Canthonini exam-

Figs 91-92. Fore right leg view. 91. Canthon tetraodon Blanchard. 92. Canthon aberrans.

ined also have the teeth distally located, except Malagoniella and Melanocanthon (Figs 99- 101). The size and orientation of the teeth on the tibia vary among species. The anterior tooth is usually larger than the second, and this is in turn larger than the third. In C. lunatus tibialis and C. maldonadoi the anterior tooth is larger than the second, much more so than what is usually observed in other species of Canthon (Fig. 102). In general, species with teeth on the anterior half of the tibia have them laterally oriented, whereas species with apical teeth have them directed obliquely. One feature that has been traditionally used in the separation of subgenera is the shape of the anterior margin of the tibia, which can be transverse or oblique. The most common pattern in species of Canthon is the tibia with the anterior margin obliquely truncated as was clearly observed in C. bicolor (Figs 97, 98). However, much variation was observed in this feature. In general, the species of the subgenus Boreocanthon and the species of the deyrollei and pilularius lines have a transverse margin on the tibia (Fig. 94). Middle and hind legs (Figs 103-119) The medial and posterior tibiae are elongated and rectangular. The middle femur is thick and can have a fringe on its anterior margin, a feature that has been used in the definition of some subgenera of Canthon. The ventral surface of the medial femur is usually smooth and without long setae. However, in C. violaceus, C. bicolor, C. tetraodon, and Malagoniella astyanax there is a


93

95

43

94

96

small series of setae longitudinally arranged on the posterior end of the femur (Figs 103-106). The dorsal side of the medial tibia has two parallel rows of spines over the lateral margins of the tibia. With the exception of C. lunatus tibialis and the species of the subgenus Boreocanthon, all the species of Canthon studied shared this pattern (Figs 107-112). In the other genera examined, the rows of spines overlap the lateral margins of the dorsal surface, except in Canthonella. In Malagoniella we did not observe contin-

Figs 93-96. Fore right leg view. 93. Canthon ebenus (Say). 94. C. deyrollei Harold. 95. C. triangularis (Drury). 96. C. aequinoctiulis Harold. Scale bar = 1mm.

uous parallel rows of spines as in Canthon. In most of the species the spines of the internal row are thin and close together forming a comb-like structure. In species of the subgenus Boreocanthon a continuous row of spines was not observed; there are fewer spines on the inner row (less than ten) and they are widely separated (Fig. 108). In C. violaceus the outer row is interrupted before reaching the posterior end of the tibia (Fig. 109), and in C. staigi the outer row of spines begins approximately at the posterior half

44

Medina. C. A.. C. H. Scholtz & B. D. Gill. Morohological variation and systematics of Canthon (Scarabaeinae)

of the tibia (Fig. 110). In species of the subgenus Boreocanthon the outer row has more than one spine arising from the same point, in contrast with the other species, which have a single spine at each point (Fig. 108). In M . astyanax the outer

row has setae spread on the anterior half of the tibia and then small clumps of setae. In several species of Canthon the posterior half of the dorsal face of the middle tibia has small tubercles with setae. In C. tetraodon the

97

98

99

100

Figs 97-100. Fore right leg view. 91. Canthon fernoralis (Chevrolat). 98. C. bicolor Laporte. 99. Hansreia aflnis (Fabricius). 100. Sylvicanthon bridarollii (Martinez). Scale bar = 1 mm.


45

102

101

y

Figs 101-102. Fore right leg view. 101. Deltochilum gibbosum (Fabricius). 102. Canthon lunatus tibialis. Scale bar = 1111111.

integument is raised forming a small transverse carina (Fig. 111). This carina crosses the dorsal face of the tibia transversally and has spines over its surface. In other species of Canthon, mainly in the subgenera Boreocanthon and Canthon (including the pilularius group and C. aberruns), small protuberances with spines on top were observed, next to the main outer row of spines (Figs 108, 112). In some species of the subgenera Glaphyrocanthon (C. angustatus, C. femoralis, C. politus, C. semiopacus), Trichocanthon (C. sordidus), Peltecanthon (C.staigi), and also in C. quinquemaculatus, C. perseverans, C. septemmaculatus, and C. triangularis, there are one or more extra spines on the posterior half of the tibia, next to the outer row of spines (Figs 113-116). Only in specimens of C. pallidus were no extra spines or setae observed near the outer row of spines (Fig. 117).

At the distal end of the middle tibia there are two spurs, one larger than the other. In the posterior tibia only one spur is present, a character common to all Scarabaeinae, except in species of Melanocanthon, which have two well-developed spurs. The tarsi of the middle and hind legs are similar. The tarsomeres are usually triangular. The size of the first tarsomere of the hind leg relative to the second one has had taxonomic value. In the species of Canthon examined however, differences in the size of the tarsomeres were not found; most species have the first tarsomere as long as the second. Only in C. tetraodon the second tarsomere is slightly longer than the second, as is in the genus Sylvicanthon. In the genera Scybalocanthon the basal tarsomere is shorter than the second, and the fifth is as longer as the second. These are useful for differentiating these

Medina, C. A., C. H. Scholtz & B. D. Gill, Morphological variation and systematics of Canthon (Scarabaeinae) -

46

103

105

106

genera from Canthon with the exception of C. sordidus (subgenus Trichocanthon), which also have these features. The tarsi of Scybalocanthon also show differences with respect to those of Canthon; in Scybalocanthon the tarsomeres are rectangular, usually thin and without separations between them, which gives the tarsi the appearance of a complete block (Figs 118-119). Elytra (Figs 120-128) In the Scarabaeinae, the elytra completely cover the abdomen except for the pygidial area. In Canthon the elytra are rectangular and slightly convex, with the margins curved inward. In some species of Canthon the basal and humeral regions of the elytra have gibbosities and protuberances. These protuberances are well-developed in species of the subgenus Nesocanthon (C. callosus and C. violaceus). In species of the subgenus Boreocanthon, these protuberances are located medially along the base of the elytron. In other species they are restricted to the humeral region, and are smaller (e.g., C. chalcites, C. sordidus, C. lunatus tibialis, C. maldonadoi and C. tetraodon). Canthon species have nine elytral striae. The striae can be well-marked or only slightly indicated on the elytra; usually the well-marked striae are present in species with coarsely sculptured elytra, whereas the slightly impressed striae are present on very smooth and glossy ely-

Figs 103-106. Ventral view on the femur of the middle leg. 103. Cunthon violaceus (onvier). 104. C. tetraodon Blanchard. 105. C. bicolor Laporte. 106. Malagoniella astyanax (Blanchard). Scale bar = 1 mm.

tra. The humeral striae can have a thin keel that runs over the anterior half of the elytron. This keel is well marked (e.g., C. bicolor, C. staigi, and C. triangularis), whereas in other species (e.g., C. praticola, C. cyanellus, C. deyrollei and C. fulgidus) it is less pronounced. The humeral keel can show intraspecific variation. Robinson (1948) reported variation in the presence of this keel in individuals of C. probus. In other Canthonini, the humeral keel is also present in M. ast,yanax and in the genus Deltochilum, in which this keel is well-developed and an important character in the taxonomy of this group. In many species of Canthon, there are small tubercles among the elytral striae at the base of the elytra. These tubercles vary in their location, between the different striae, and can vary in number and size (Figs 120-121). They are also present in Deltochilum gibbosum, Malagoniella astyanax, and in the genera Melanocanthon, Anisocanthon and Scybalocanthon. Tubercles were not present at the base of the elytra in C. fulgidus, C. septemmaculatus, C. tetraodon, C. staigi, C. sordidus, and C. triangularis, or in Canthonella and Cryptocanthon. In several groups of Canthon the striae of the elytra are weakly impressed and barely noticeable. However, in species of the pilularius group, the striae are deep, furrow-like in shape, or form continuous grooves along the elytron (Fig. 123). In the species of the subgenus Boreocanthon the striae are also formed by furrows; in some spe-


cies the furrow can be wide and well-marked as in C. nyctelius. In Canthon, the striae are usually formed by thin lines interrupted by smooth areas. The striae are formed by continuous lines only in the species of the pilularius group, in C. lunatus tibialis, C. ebenus, and C. praticola. In other genera of Canthonini the striae are more developed than in Canthon, and can be formed by a wide fringe and with punctures in the middle as was observed in species of Deltochilum and Hansreia (Figs 122, 127, 128). In some spe-

107

cies of Canthon the striae are wide at the base of the elytron where the sculpture is more marked, but they become slender and weak on the smoother and polished areas of the elytron (e.g., C. politus; Fig. 120). The elytra of Canthon are generally glabrous, although some species have thick setae. These setae can be arranged in rows among the striae of the elytron, as in C. sordidus and A. villosus, or be randomly distributed over the surface as in C. juvencus.

108

111 110

47

Figs 107-112. Dorsal face of the left middle tibia. 107. Canthon lunatus tibialis Schmidt. 108. C. ebenus (Say). 109. C. violaceus (Olivier). 110. C. staigi (Pereira). 111. C. tetraodon Blanchard. 112. C. chalcites (Haldemann). Scale bar = 0.5 mm.

48

Medina, C. A., C. H. Scholtz & B. D. Gill, Morphological variation and systematics of Cunfhon (Scarabaeinae) h

114

113

116

115

117

I

Figs 113-117. Dorsal face of the left middle tibia. 113. Cunthon simplex LeConte. 114. C. sordidus Harold. 115. C. quinquemaculutus Laporte. 116. C. femorulis (Chevrolat). 117. C. pullidus Schmidt. Scale bar = 0.5 IIM.

monilifer, C. sordidus, C. humectus, and C. lunatus tibialis; a third pattern consists of widely spaced The dorsal appearance of most species of Can- minute punctures, which can be observed only at thon is smooth, without marked sculpturing. magnifications of 60x or higher under diffuse However, in some species, particularly those of light. This pattern is common in species of Canthe subgenus Boreocanthon, the texture is thon and it was observed in C. quinquernacoarse. Species in this subgenus have the surface culatus, C. femoralis, C. cyanellus, C. politus, and of the body with granules and marked punctures C. quadriguttatus, among others. The last pattern (Fig. 123). Four main sculpturing patterns were is present in species with very smooth and shinfound on the elytra of the species of Canthon ing elytra such as C. violaceus, C. fulgidus, C. bicoexamined. The first is a sculpturing of large and lor, species of the viridis group, and some species small granules that was observed in C. praticola, that have translucent elytra like C. angustatus. C. ebenus, and C. chalcites (Fig. 123). The second The texture of the elytra in these species is withpattern consists of small granules uniformly distrib- out granules and punctures (Figs 124-126). uted on the surface of the head and elytra, as in C.

Sculpture (Figs 123-128)


49

118

Figs 118-119. Posterior right tibia view. 118. Canthon quinquemaculatus. 119. Scybalocanthon pygidialis. Scale bar = 1nun.

Pygidium (Figs 130-133)

Male genitalia

The pygidium is triangular, wider than long and usually convex. Some species have the pygidium more convex and in some species it is a conical projection, as in C. speculifer and species of the subgenus Goniocanthon. The pygidium is separated from the prepygidium by a carina, which is generally well-marked in species of Canthon. The prepygidium is a short sclerite that varies in length, as well as in the presence and shape of the longitudinal sulcus that crosses the prepygidium in its medial part (Figs 130-133). The presence of a carina on the anterior margin of the pygidium has been useful in the differentiation of genera of Canthonini. According to the literature, genera such as Anisocanthon and Scybalocanthon differ from species of the genus Canthon because they lack both a carina and keel on the anterior region of the pygidium (Martinez & Pereira 1956, Halffter & Martinez 1977). However, species of Canthon such as C. septemmaculatus, C. monilifer, and C. triangularis do not have a carina on the anterior margin of the pygidium either (Fig. 132). According to Howden & Gill (1987), C. hartmanni also lacks a fringe on the anterior margin border of the pygidium.

Aedeagus (Figs 134-137) The aedeagus are of taxonomic value in Canthon (Halffter 1961) and related groups (Halffter & Martinez 1977). The form of the parameres is of taxonomic importance and marks the difference among different types of aedeagi. With the exception of C. aberrans, the parameres in most species of Canthon are symmetrical. In other genera of Canthonini, mainly from Australia and Africa, species with asymmetrical parameres are common. The shape of the parameres in Canthon differs greatly; four main types of aedeagi were observed in the species examined. One type of aedeagus has triangular parameres (e.g., C. violaceus, C. perseverans, C. bicolor, C. aequinoctialis, and C. luteicollis; Fig. 134). This kind of aedeagus is also common in many other genera of Canthonini and Ateuchini. A second type of aedeagus has more or less rectangular parameres, with the apex completely truncated transvenally, as in some species of the subgenus Cunthon (e.g., C. humectus, C chiriguano), in the subgenus Glaphyrocanthon (e.g., C. angustatus, C. femoralis, C. semiopacus, C. viridis), and in

50

Medina. C. A., C. H. Scholtz & B. D. Gill. MorDhological variation and svstematics of Cunthon (Scarabaeinae) .

..

120

.

. . .

these species the ventral side is deeply sinuated forming an outward projection (Fig. 136). In the other genera of Canthonini the parameres were generally triangular, with the exception of Hansreia, which has rectangular and distally truncated parameres as in species of Canthon. The aedeagus in Canthonella is completely distinct from that of all other species of Canthon or Canthonini examined; the medial lobe is more developed and the parameres are reduced. A reduced paramere is also present in other genera of Canthonini, such Canthochilum and Sinapisoma from America, and Bohepilisus from Africa. Internal sac of the aedeagus (Fig. 138)

The internal sac of the aedeagus is an elongated membranous bag in which different structures can be distinguished (Fig. 138). The internal sac is encased within the chitinous capsule of the aedeagus. Once the sac is extracted different scler121 ites surrounded by a thick membrane can be detected. Zunino (1978) called these sclerites accessory lamellae. He also described a sclerotized structure for Onthophagus, the lamella copulatrice, located posteriorly to the accessory lamellae. In Canthon the area posterior to the sclerites is generally widened and corrugated, but it is not a defined structure as in Onthophagus, nor like the chitinous structures found in some species of Deltochilum subgenus Hybomidium. In the medial part of the internal sac is an 122 area where the membrane is internally covered by small spines that give it a corrugated appearFigs120-122. Detail of the base of the elytra, showing tu- ance. In this area there are sclerotized structures bercles and striae. 120. Canthon politus Harold. 121. C. humectus (Say). 122. Hansreia afinis (Fabricius). Scale bar formed by groups of spines of variable shape =lm. and size, which we shall refer to as brushes of the internal sac. Zunino (1978) referred to this other species such as C. triangularis, C. septem- structure as the raspula. maculatus, C. lunatus tibialis, C. fulgidus, and In the posterior end of the internal sac there C. staigi (Fig. 135). A third type of aedeagus is are two slightly sclerotized plates, called temones shared by species of the subgenus Boreocanthon, (D’Hotman & Scholtz 1990). Before unfolding as well as the subgenus Canthon (pilularius the internal sac, the temones are folded, one on group). These species have boot-shaped para- each side of the sac. When the sac is stretched meres, with an inwardly curved tooth in a ven- they look like flat plates. Their shape varies. tral position (Fig. 137). The tooth, which can vary from sharp to truncate, was invariably pre- Sclerites of the internal sac sent in all species of this group. A fourth type of (Figs 139-163, 165-173) aedeagus was observed in other species such as C. politus and C. cyanellus. The paramere in Different types of sclerites are found in the interthese species narrows toward the apex and the nal sac of Scarabaeinae beetles: a circular-shaped ventral side is sinuate. This type was also ob- sclerite, which is always noticeable, an elongated served in C. maldonadoi and C. monilifer but in sclerite, a plate-shaped sclerite, and a small scler-


123

51

124

126

125

128

127

129

Figs 123-129. Sculpture of elytra and clypeus dorsal view. 123. Cunthon chalcites (Haldemann). 124. C. fulgidus (Redtenbacher). 125. C. indigaceus LeConte. 126. Detail enlargement of inset in Fig. 125, showing the striae of the elytron. 127. Hansreia ufinis (Fabricius). 128. Deltochilum gibbosum (Fabricius). 129. Detail of the clypeus of C. fulgidus (Redtenbacher). Fig. a magnification = 20 x, Figs 124, 126, and 128 magnification = 40 x, Fig. 125 magnification = 15 x, Fig. 127 and 129 magnification = 30 x.

ite, which can have different shapes (Figs are, collectively, an important source of charac139-162). These four types of sclerites are the ters. Intrageneric variation in the structures of most common and constant to the species of Can- the internal sac is generally small, and a pattern thon examined, although more than four sclerites among genera is recognised. In genera of were found in a few species, e.g., C. aequinoctialis Canthonini, such as Paracanthon Balthasar, Epirand C. triangularis. inus Reiche, and Gyronotus Van Lansberge, the By examining the shape and the relative posi- array, shape, and position of the sclerites has a tion of the sclerites, we can be fairly certain of consistent intrageneric pattern (C. A. Medina, their homology. The type, shape, relative posi- personal observations). However, studying the tion, and degree of sclerotization of the sclerites variation of the internal sac within Canthon, a

52


130. Figs 130-133. Pygidium. Canthon politus Harold. 131. C. indigaceus LeConte. 132. C. triangularis (Drury). 133. Scybalocanthon moniliatus (Bates). Scale bar = 1mm.

clear pattern for the whole group is not apparBased on the internal sac of the aedeagus, ent. Small groups of species of Cunthon share three species groups within Cunthon are clearly the same types of sclerites, but there is no consis- identifiable. One group is formed by species of tent pattern for the genus as a whole. the subgenus Fruncmonrosiu, a second group by

’

Figs 134-137. Lateral view of the aedeagus. 134. Canthon aequinoch’alis Harold. 135. C. staigi (Pereira). 136. C. rnonilifer Blanchard. 137. C. deyrollei Harold. Scale bar = 1mm.


s-

53

-I"-+

k.

Fig. 138. Scheme of the internal sac of the aedeagus of Cunthon bicolor Laporte. sc = sclerites, br = brushes of internal sac, te = temones. Scale bar = 2 mm.

species of subgenus Glaphyrocanthon, and a ever, as the genus Deltochilum is not closely rethird group is formed by species of the pilularius lated to Canthon, it was not studied in great group. Two of these groups have support in the detail. cladogram (Fig. 164) and they are discussed later. Outside of Canthon different types of inter- Circular sclerite nal sac are shared by groups of taxa. The genera Magathopa and Malagoniella have the same type The circular sclerite is a conspicuous structure of of internal sac and sclerites. The species of the the taxa studied. This sclerite seems to be a plegenus Scybalocanthon examined also have a dis- siomorphic structure since it is also present in tintic internal sac. In the genus Deltochilum dif- members of the tribes of tunnelling beetles such ferent types of sclerites were observed; species of as Ateuchini and Coprini (C. A. Medina, persothe subgenus Calhyboma (0.hypponum, D. mexi- nal observations), from which the roller beetles canum) have a different circular sclerite from probably evolved. This sclerite is also present in those from the subgenus Hybomidium. In addi- other tribes of roller beetles such as Scarabaeini tion in others species (e.g., D. orbignyi, D.furca- and Gymnopleurini, which ease to confirm the tum, D. parile, D.rubripenne) internal sac sclerites idea of its plesiomorphic condition. Despite the different from those found in the subgenera Cal- obvious external differences among the genera hyboma and Hybomidium were observed. How- Scatonomus Erichson (Coprini), Anomiopus

54

Medina, C. A,, C. H. Scholtz & B. D. Gill, Morphological variation and systematics of Canthon (Scarabaeinae)

139

14

144 Westwood (Ateuchini), and Canthon (especially C. virens), the similarity of their circular sclerites is striking. We refer to this type of sclerite as the circular sclerite due its constant circular shape in most of the structure. However, this sclerite has also been known as the virgular sclerite (Matthews 1974), or the ring sclerite (Reid 2000). The circular sclerite is generally located transversally to the other sclerites, and can be surround by a clear transparent membrane. The circular sclerite is basically formed by a circular portion, which we have called a ring, and a handle-shaped extension. In the common type of circular sclerite found in Canthon, the ring and the handle are completely fused (Figs 168-170). The shape of the ring varies greatly; it can be more rounded or oval. Generally, the ring has a protuberance, which can be well developed or only slightly noticeable (Figs 161, 171). The handle is usually more chitinous than the ring. It can be short and wide, or elongated and narrow.

Figs 139-144. Circular sclerite of the internal sac of Canthon (type I). 139. C. humectus (Say). 140. C. triangularis (Drury). 141. C. quinquernaculatus L,aporte. 142. C. pilularius (Linnaeus). 143. C. violaceus (Olivier). 144. C. bicolor Laporte. Figs 140, 142, 143 and 144 scale bar = 0.5 mm, Figs 139 and 144 scale bar = lmm.

Variation in the circular sclerite is enormous within Canthon and different types of circular sclerites can be found, even among the species of the same subgenus. One of the most common types of circular sclerite has a thick handle and a partially thickened ring with a distinctive protuberance (referred in the list of characters, Appendix 3, as circular sclerite type I; Figs 139-142). In another type of circular sclerite, which is present in a group of species of the subgenus Glaphyrocanthon, the protuberance can be enlarged and part of the ring is thick and more heavily sclerotized (Figs 159, 161, 163). The handle in this type of sclerite is short. A circular sclerite with a large, slender ring and a short handle, lacking a protuberance, was also observed (C. bicolor, C. staigi, C. violaceus, and H. afsinis; Figs 143, 144). Outside of Canthon different types of circular sclerite were observed. In the genus Deltochilurn, subgenus Calhyboma, the circular sclerite is like a plate with a hole, and with very short handle (Figs 165, 166). In the subgenus Hybomidium


145 14’

\

the sclerite has a well-developed handle with a prominent process and a slender ring that is not strongly sclerotized and has small deformations (Fig. 167). Malagoniella and Megathopa have a circular sclerite characterised by a well-developed handle with a prominent process and a relatively small ring (Fig. 173).

55

Figs 145-148. Elongated sclerites of the internal sac of the aedeagus. 145. Deltochilum hyponnum (Buquet). 146. C. monilifer Blanchard. 147. Canthon quinquemaculatus Laporte. 148. C. septemmaculatus (Latreille). Scale bar = 1mm.

This type of sclerite was found in all species examined, except in C. gomezi. It is absent in other small Canthonines such Canthochilum Chapin, Agumopus Bates, and in some genera from Africa and Australia. However, this sclerite is common in other genera of Canthonini from Africa, Australia, and Madagascar, and even in some genera of the Ateuchini and Coprini tribes (C. A. Medina personal observations).

Elongated sclerite Different plates superimposed form the elongated sclerite. This sclerite can vary in its shape and size, it is usually enlarged at one end, and has a projection that narrows toward the other end. These sclerites have some strongly sclerotized areas while others are poorly sclerotized (Figs 145-148). Among most species of Cunthon the elongated sclerite varies in size from 0.3-2.0 mm; C. stuigi was the only species of Cunthon with a longer elongated sclerite 3.0 mm, as long as those found in species of Deltochilum.

Plate-shaped sclerite The plate-shaped sclerite is a constant structure in the internal sac of Scarabaeinae beetles, with a large range of variation. This structure can generally be recognised by its position lateral to the handle side of the circular sclerite, and always laterally to the elongated sclerite. Sometimes the plate is concave, and in that case the elongated and small sclerites are located in the concave side of the plate. The different variations of the plate sclerite are more difficult to

56

Medina, C. A., C. H. Scholtz & B. D. Gill, Momholonical variation and svstematics of Canthon (Scarabaeinae)

14

152

155 describe, as the structure can take different shapes in different species (Figs 149, 1.58). Some patterns were found in small groups of species, which are described latter. Brushes of the internal sac (Figs 174-179)

The shape, number, and size of brushes of the internal sac vary among species of Canthon. Some species have brushes with fine, densely packed bristles that are clustered to form a de-

Figs 149-157. Sclerites of the internal sac of the aedeagus Francmonrosia group. 149-151. Canthon dives Harold. 152-154. Canthon Zatipes Blanchard. 155-157. Canthon rutilans Harold. dp = distal process. Scale bar = 0.01 mm.

fined structure. C. lunatus tibialis has only one brush formed by thick, dispersed bristles, while species of the pilularius group have a crescentshaped shaped brush, formed by closely packed bristles (Fig. 179). In C. indigaceus, C. deyrollei, and C. sordidus the bristles are thicker, shorter, and grouped without forming a defined structure (Fig. 17.5). Generally there are two brushes, as in C. quinquemaculatus, C. columbianus, and C. cyanellus, or more than three as in C. triangularis, C. monilifer, and C. septemmaculatus (Figs 176,


57

I 163

177). The brushes of S. bridarollii, are formed by broad, short spines (Fig. 178). C. aequinoctialis and H. ajfinis have a compact and well-sclerotized structure, surrounded by small spines. In some species of Canthon (e.g., C. aberrans, C. bicolor, C. luteicollis, C. violaceus, C. tetraodon, C. perseverans, C. staigi, C. praticola, C. ebenus, and C. simplex) the middle part of the internal sac lacks well-defined brushes, and this area has a strip in which the membrane is internally covered by evenly spaced, uniform spines (Fig. 174).

Figs 158-163. Sclerites of the internal sac of the aedeagus Femoralis group. . 158-159. Canthon rubrescens Blanchard. 160-161. Canthon femoralis (Chevrolat). 162-163. Canthon angustatus Harold. Scale bar = 0.01 mm.

Results of the cladistic analysis The analysis of 82 characters and 39 taxa resulted in eight most parsimonious cladograms of 298 steps (Ci = 37, Ri = 65). Eight nodes where collapsed in the strict consensus tree (Fig. 164). This topology shows a well-supported group comprised of most of the genera of Canthonini analysed (node A); only the genus Cryptocanthon falls outside of this large clade. Cryptocanthon, as well as Canthonella, are morphologically very distant from the other American genera of Canthonini, and they do not share important characters from the epipharynx, ventral prono-


58

Canthonellagomezi 7 I9 41 88 70

p-wM-b- Cryptocanxhonsp

‘1A

9 39 70 71 73 77 70

Dellochilumgibbosum Malagoniella astyanax

Megathopa punctatostrlata

1 11 13 15 17 1S 11 13 31 83 18

Canthon smaragfdulus

7

14 I8 I0 25

23 53

Jo 4 70 78 79

7 Hansreia afffnis

D 10 20 30

14 14 18 58 84 08 71 73 74

33 41 44

i a 20 30

sw

Scybalocanthon pyaidkrlis

a7 80 71

7 Scybalocanthon moniliatus 34

I 5 12 20 22 26 28 32 52 55 113 77 80

F I4 07 78

fl-D-

1

5 20 41 45 55 85 87 71

-

Canthon chalcltes

2 I1 34 37 49 53 78 80

L

Canthon imitator Canthon plluiarius

1

7 4 5 14 30 33 34 37 88 76

Canthon aberrans

Canthon ietraodon

Fig. 164. Strict consensus tree form 8 cladograms (298 steps, Ci = 37, Ri = 65). Number below branches are branch support values. Black hatchmarks indicating changes without homoplasy, white hatchmarks indicating changes with homoplasy.


59

/--

Figs 168-170. Sclerites of the internal sac of the aedeagus. 168. Canthon tetraodon Blanchard. 169. C. politus Harold. 170. C. fulgidus (Redtenbacher). ebr = external border of ring, ha = handle, hap = handle process, hed = distal end of handle, hpe = proximal end of handle, rg = ring. Scale bar = 0.5 mm.

Figs 165-167. Different types of circular sclerites in species of Deltochilum. 165. D. mexicanum Burmeister. 166. D. hyponumm (Buquet). 167. D. orbignyi Blanchard. ha = handle, hap = handle process, rg = ring. Scale bar = 0.5 mm.

tum, or male genitalia. Malagoniella and Megathopa form a separate clade (node C) basally on the cladogram. Hansreia, along with three additional species of Canthon (node E), are linked to the rest of the taxa in a large polytomy (node F). In this node most of the species of Canthon are dispersed throughout the clade with Anisocanthon, Melanocanthon, Sylvicanthon, and Scybalocanthon. The latter genus forms a well-supported group with C. sordidus (subgenus Trichocanthon,

node G). Several species of the subgenus Glaphyrocanthon are grouped in a single clade (Femoralis group, node K), and all the species of the subgenus Fruncmonrosia form a supported clade (node P). From this cladogram it is evident that Canthon is not a monophyletic group, as there is no clade that clusters all species of Canthon. Unfortunately only a few species from the other genera were included in the analysis (with the exception of the genus Scybalocanthon), so we cannot speculate as to whether genera such as Anisocanthon, Melanocanthon, or Sylvicunthon are natural species groups.

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Medina, C. A., C. H. Scholtz & B. D. Gill, Morphological variation and systematics of Canthon (Scarabaeinae) -

this subgenus, such as C. serniopacus, C. acutus, C. viridis, C. vasquezae, and some unidentified species related to C. quadriguttatus, sclerites totally different from those present in the Femoralis group were observed. Glaphyrocanthon, with 42 species, is the second largest subgenus of Canthon; not all the species of the subgenus were studied. Until the internal sac of all the species are compared, we cannot be sure about the validity of this group. However, differences among the species in other structures (e.g., parameres, shape of the eyes) suggest that Glaphyrocanthon sensu strict0 is not a natural group, and needs to be reviewed.

Francrnonrosia group (node P) The subgenus Francrnonrosia appears to be a natural group of species. This group is supported mainly by characters from the internal sac. Among the synapomorphies of this group of species are a circular sclerite with a large and conspicuous protuberance, a plate-shaped sclerite with an apical process, and the presence of a fourth small sclerite located closer to the plate sclerite (Figs 149-157). A tooth in the fore femur is also common to these species. As the latter character is diagnostic for the subgenus, we assume that it is also present in the three species of the subgenus not examined. It will be necessary to examine the internal male genitalia of the remaining species to conFigs 171-173. Different types of circular sclerites of the in- firm that they have the same pattern in the sclerternal sac of Canthonini. 171. Sylvicanthon bridarollii (Mar- ites of the internal sac. The number of clypeal tinez). 172.Melanocanthon bispinatus (Robinson). 173.Megathopa punctatostriata (Blanchard). ha = handle, hap = handle teeth is not a useful character for this group, as process, hpe = proximal end of handle, rg = ring. Figs 171 some species have two, while others have three and 172 scale bar = 0.5 mm. Fig. 173 scale bar = 0.25 mm. clypeal teeth. Variation in the femoral tooth is also large: C tetraodon and C. dives have prominent teeth; while in C. ruitilans and C. latipes it Fernoralis group (node K) is less developed. This group is formed by a group of species of the subgenus Glaphyrocanthon, including C. angustatus, C. fernoralis, C. luteicollis, and C. rubres- Discussion cens. Although C. brunneus, C.columbianus, and C. pallidus were not included in the cladistic ana- Different authors have proposed different generlysis, these species also have the same type of ic limits for Canthon since the genus was first proposed. We contend that the successive diviinternal sac. A concave, plate-shaped sclerite is distinctive sions and groupings of species of Canthon (Taof this group. Both the circular and the plate ble 1) in different genera and subgenera has sclerites have a unique shape that is common been a consequence of deficient diagnoses. Our only to this group of species (Figs 158-163). Not study shows that the characters used to delimit all the species of Glaphyrocanthon examined Canthon are not found consistently within the present this type of sclerite. For instance C. poli- group. Most of the characters used by Halffter & tus has completely different circular and plate- Martinez (1977) in the diagnosis of Canthon are shaped sclerites (Fig. 169). In other species of general characters that not only show wide varia-

61


174

175

176

177

179

178 Figs 174-179. Detail of brushes of the internal sac of the aedeagus. 174. Canthon luteicollis Erichson. 175. C. indigaceus LeConte. 176. C. quinquemaculatus Laporte. 177. C. triangularis (Drury). 178. Sylvicanthon bridarollii (Martinez). 179. C. pilularius (Linnaeus). Figs 174, 176 magnification = 10 x , Figs 175, 177, 179 magnification = 20 x , Figs 179 magnification = 40 x .

62

Medina. C. A,. C. H. Scholtz & B. D. Gill, Morphological variation and systematics of Cultthon (Scarabaeinae)

tion among the species studied, but are also present in other genera of Canthonini. Some characters are poorly defined leading to ambiguous interpretation. Most morphological structures exhibit wide variation in Canthon and related genera. Characters such as clypeal teeth, shape of the eyes, excavation of the thorax, and shape of the parameres can vary widely even within a small group of species or a subgenus. This has led to the generalized use of combinations of characters in the diagnoses of many genera, producing unstable classifications. Most traditional classifications of dung beetles are based on morphological similarity that has arisen as a result of similarity in habitat, dung exploitation, or ecological niche, and not necessarily as a result of common ancestry. Modern phylogenetic systematics has given us a philosophical framework and a rigorous methodology to produce more accurate (i-e., phylogenetic) classifications, with implicit information about the evolutionary history of the group under study (Hennig 1966). In many groups of roller beetles the external morphology has been reduced to a very plain and simple shape, so that many of the morphological similarities among species groups are highly homoplasic and poorly informative. The results of our cladistic analysis have shown that even though some groups are well supported, the general similarity in characters of external morphology results in extensive homoplasy in the cladogram (Fig. 164). Most of the synapomorphies in the tree correspond to characters from internal structures such the epipharynx and the internal male genitalia. These characters are unique, and so they are real synapomorphies on which a reliable classification can be based. Another important result of this study concerns the variation of internal structures. We consider the morphological variation of internal structures displayed by the species under study to be important. Studying the variation of these morphological structures helped to differentiate patterns among the various groups. When different species of one group were examined, such as in the subgenus Francmonrosia, the differences of the morphological structures among the species within the group versus outside of the group, were more clearly defined. The same result occurred with other groups of species, such as the Femoralis group. In this group, members have a distinctive pattern in the internal sac, which can be differentiated from other members

of the same subgenus, and from other genera. It is also important to examine the morphological variation among individuals of the same species, as some features such as colour and size can vary greatly among the groups studied. The analysis of the variation of the epipharynx revealed characters that differentiate groups at different levels. For example, five of the synapomorphies for the principal node in the cladogram (node A; Fig. 164), those that separate Canthonella and Cryptocanthon from the rest of the genera, are characters from the epipharynx. The lateral combs of the epipharynx are also an important synapomorphy for the large group of species that includes Canthon and the most closely related genera (Anisocanthon, Melanocanthon, Scybalocanthon, and Sylvicanthon; node F). This study is an exploratory analysis and is not intended as a revisional paper to resolve the taxonomic problems among the groups. Our results show how classifications can be improved when they are based on a detailed study of internal morphology, searching for diagnostic characters to define natural groups of species. The genus Canthon is clearly a complex assemblage of groups of species. Most of the species currently under the name Canthon are similar in external features, a similarity that is perhaps due to their common behaviour of rolling balls of dung, or a function of living in similar habitats such as tropical forests and savannas. However, it seems that the internal morphology of the species of Canthon is more complex, revealing both differences and patterns among the groups of species. A larger systematics study including all species of the genus is necessary to define unequivocally these groups of species. In addition, other internal structures not included here, such the female genitalia, mouthparts other than the epipharynx, and internal structures of the abdomen, may have characters that are congruent with the patterns exhibited by the internal male genitalia, and thereby support a revised classification.

Acknowledgements Different people supported us during the course of this project. We received suggestions and help from Jonathan Coddington, Michael Alberico, Franqois GCnier, Rafael Miranda, Michael Sharkey, Daniel Peck, Ranulfo Gonzales, Mila Coca, Jorge Llorente, Eric Matthews and Keith Philips. Frank Krell, John Miles kindly reviewed the manuscript and their valuable comments helped to improve the final version. Specimens were provided by the Museum of the Alexander Von Humboldt Institute, Canadian Museum of Nature,

Mitt. Mus. Nat.kd. Berl.. Dtsch. entomol. Z. 50 (2003) 1 Alejandro Lopera’s personal collection, and Fernando Vaz de Mello private collection. Estela Monteresinos from Universidad de Rio Cuarto in Argentina and Patricia Gonzales from the Universidad de la Republica in Uruguay, also provided some specimens. The Coral Reef Research group at Universidad del Valle allowed us to use their image analysis equipment. William Yara did part of the drawings of the figures. C. A. Medina wants to express her gratitude to additional people and institutions that have supported her research in different ways. Special thanks are due to John Miles, Fernando Fernandez, Patricia Uribe, Patricia Chac6n and Fernando Gast. Special thanks to Vasily Grebennikov for his constant encouragement and his valuable advice in the final art drawings, and to Fernando Vaz de Mello for his multiple answers. The most special acknowledgement to Fernando Zapata for all his valuable help in the translation of the manuscript, and for his irreplaceable loving support. This study is part of a thesis submitted in partial fulfilment of requirements for a M.S. degree at the University of Pretoria. The project was financially supported by the Foundation for the Promotion of Research and Technology of the Banco de la Republica, Colombia.

References Bates, H. W. 1887. Biologia Centrali-Americana. - Coleoptera 2 (2): 25-160. Bremer, K. 1994. Branch support and tree stability. - Cladistics 10: 295-304. Castellanos, M. C., F. Escobar S., & l? R. Stevenson 1999. Dung beetles (Scarabaeidae: Scarabaeinae) attracted to Woolly monkey (Lugothrix Lugothricha Humboldt) dung at Tinigua National Park, Colombia. - The Coleopterists Bulletin 53: 155-159. D’Hotman, D. & C. H. Scholtz 1990. Comparative morphology of the male genitalia of derived groups of Scarabaeoidea (Coleoptera). - Elytron 4 3-39. Diaz, R. A. 1997. Ecologia y comportamiento de escarabajos rodadores del estiercol (Scarabaeidae: Scarabaeinae) de selvas y pastizales en 10s Tuxtlas, Veracruz, MCxico. Universidad Nacional Autonoma de MCxico, Facultad de Ciencias, Tesis de Maestria, 174 pp. Edmonds, W. D. 1972. Comparative skeletal morphology, systematics and evolution of the Phanaeine dung beetles (Coleoptera: Scarabeidae). - The University of Kansas Science Bulletin 49:731-874. Favila, M. E. & G. Halffter 1997. The use of indicator groups for measuring Biodiversity as related to community structure and function. - Acta Zooldgica Mexicana 72: 1-25. Gill, B. D. 1991. Dung beetles in tropical American forests, pp. 211-229. In Hanski, I & Y. Cambefort (Eds.). Dung Beetle Ecology, Princeton (Princeton University Press). Goloboff, P. 1995. NONA, Version 2.0. - Fundacion e Instituto Miguel Lillo, TucumBn, Argentina. Halffter, G. 1958. Dos nuevos gCneros de Canthonini (Col: Scarabaeidae). - Ciencia Mexicana, 17 (10-12): 207-212. - 1961. Monografia de las especies norteamericanas del gCnero Cunthon Hoffsg. (Coleopt., Scarab.). - Ciencia, Revista Hispanoamericana de Ciencias Puras y Aplicadas 20 (9-12): 225-320. Halffter, G. & W. D. Edmonds 1982. The nesting behavior of dung beetles (Scarabaeinae) - an ecological and evolutive approach. - Instituto de Ecologia A.C., MCxico, 177 pp. Halffter, G. & A. Martinez 1966. Revision monografica de 10s Canthonini Americanos (Coleoptera, Scarabaeidae)

63 (I. parte). - Revista de la Sociedad Mexicana de Historia Natural 27: 89-177. - 1977. Revision monogrBfica de 10s Canthonini Americanos (IV. parte) clave para gCneros y subgkneros. - Folia Entomologica Mexicana 38: 29-107. Halffter, G. & E. Matthews 1966. The natural history of dung beetles of the subfamily Scarabaeinae (Coleoptera, Scarabaeidae). - Folia Entomologica Mexicana (12-14), 312 pp. Hanski, I. & Y. Cambefort (Eds) 1991. Dung Beetle Ecology. - Princeton, (Princeton University Press), 481 pp. Harold, E. von 1868. Monographie der gattung Canthon. Berliner Entomologische Zeitschrift 12: 1-144. Hennig, W. 1966. Phylogenetic Systematics. - University of Illinois Press, Urbana and Chicago, 263 pp. Howden, H. F. & B. D. Gill 1987. New species and records of Panamanian and Costa Rican Scarabaeinae (Coleoptera: Scarabaeidae). - The Coleopterists Bulletin 41: 201-224. Martinez, A. 1948. Notas Coleopterologicas I: un gCnero nuevo y dos especies nuevas de Canthonini (Col. Scarabaeidae) de Venezuela. - Anales de la Sociedad Cientifica de Argentina 146: 41-51. - 1950. Contribuci6n a1 conocimiento del genero Megathop a Eschsch., 1822, en la Argentina. - Revista Espaiiola de Entomologia Tom0 XXVI, (3-4): 197-269. - 1952. Scarbaeidae nuevos o poco conocidos 111 (Coleoptera). - Misi6n de Estudios de Patologia Regional Argentina, 4 159-172. - 1954. Scarabaoeidea Neotropica I. - Neotropica l(2): 27-28. - 1961. Notas sobre el Complejo Megathopa Eschscholtz, 1822 (Col. Scarab. Scarabaeinae). - Scarabaeoidea Neotropica VIII, Neotropica 7 81-86. Martinez, A. & F. S. Pereira 1956. Dois gCneros novos de Canthonini Americanos (Col. Scarabaeoidea, Scarabaeidae). - Pap& Avulsos 12 363-388. Matthews, E. G. 1974. A revision of the Scarabaeine dung beetles of Australia, I1 tribe Scarabaeini. - Australian Journal of Zoology, Supplementary Series 2 4 1-211. Nel, A. & C. H. Scholtz 1990. Comparative morphology of the mouthparts of adult Scarabaeoidea (Coleoptera). Entomology Memoir No 80, Department of Agricultural Development, Republic of South Africa, 84 pp. Nixon, K. C. 1995. CLADOS, Version 1.9.4. - Cornell University, Ithaca, NY. - 1999. Winclada (BETA) ver. 0.9.9. - Published by the author, Ithaca, NY. Pereira, F. S. 1953. Notas sinonimias (Col. Scarab.). - Dusenia 4: 387-402. Pereira, E S. & A. Martinez 1956. 0 s gCneros de Canthonini Americanos (Col. Scarabaeidae). - Revista Brasileira de Entomologia 6: 91-192. - 1959. Tres nuevos gCneros de Canthonina americanos (Coleoptera, Scarabaeidae). - Acta Zoologica Lilloana, 17 165-184. Reid, C. A. M. 2000. A complex of cryptic species in the genus Coptoductyla Burmeister (Coleoptera: Scarabaeidae: Coprini). - Memoirs of the Queensland Museum 46 (1): 231-251. Robinson, M. 1948. A review of the species of Canthon inhabiting the United States (Scarabaeinae: Coleoptera). Transaction of American Entomological Society 7 4 83-99. Snodgrass, R. E. 1935. Principles of Insect Morphology. Cornell University Press, Ithaca, 667 pp. Zunino, M. 1978. L‘armature genitale negli Onthophagini: tecniche di preparazione e criteri di studio (Coleoptera Scarabaeidea). - Suplemento a1 Bollettino della SocietB Entomologica Italiana 19: 21-26.

64


Appendix 1 List of species examined. Country = country of origin of the studied specimen(s). Collection = Museums abbreviation (see methodology). CM = Specimens in the possession of the senior author until analysis of the tribe Canthonini is completed. This material will subsequently be deposited in a recognized museum. Genera (subgenera)

Species

Country

d

9

Collection

C. ebenus (Say) C. lecontei Harold C. nyctelius Harold C. praticola LeConte C. simplex LeConte C. aberrans (Harold) C. chiriguano Martinez & Halffter C. humectus humectus (Say) C. chalcites (Haldemann) C. imitator Brown C. pilularius (Linnaeus) C. indigaceus indigaceus Harold C. deyrollei Harold C. lituratus (Germar) C. mutabilis Harold C. chiriguano Martinez & Halffter C. cyanellus cyanellus Leconte C. aequinoctialis Harold C. morsei Howden C. virens Mannerheim C. juvencus Harold C. dives Harold C. latipes Blanchard C. rutilans Harold C. tetraodon Blanchard C. acutus Harold C. angustatus Harold C. brunneus Schmidt C. championi Bates C. columbianus Schmidt C. femoralis femoralis (Chevrolat) C. femoralis bimaculatus Schmidt C. lamprimus Bates C. luteicollis Erichson C.meridionalis (Martinez, Halffter & Halffter) C. pallidus Schmidt C. politus Harold C. quadriguttatus (Olivier) C. sp. (quadriguttatus group) C. cJ:plagiatus C. rubrescens Blanchard C. semiopacus Harold C. subhyalinus Harold C. viridis (P. de Beauvois) C. vasquezae Martinez, Halffter & Halffter C. fulgidus Redtenbacher C. smaragdulus Fabricus C. callosus Harold C. violaceus (Olivier) C. staigi (Pereira) C. lunatus tibialis Schmidt C. muticus Harold c . sp. C. sordidus Harold C. monilifer Blanchard C. septemmaculatus (Latreille) C. maldonadoi Martinez C. quinquemaculatus Laporte

USA USA Mexico USA USA Colombia Argentina Mexico USA USA USA Mexico Guatemala Colombia Colombia Argentina Colombia, Mexico Colombia Panama Brazil Colombia Argentina Brazil Uruguay Paraguay Venezuela Panama Co1ombia Mexico Colombia Mexico Colombia Panama Colombia Colombia

1 1 0 3 1 4 1 2 3 2 3 2 1 2 2 1 8 3 1 2 1 1 2 1 2 1 10 1 1 2 4 1 1 8 0

0 1 2 1 1 2 1 1 3 1 2 2 1 1 0 1 4 1 1 1 1 0 0 0 1 1 3 1 1 3 3 0 1 4 1

CM CM BDGC, CM CM, CM IAVH, CM, UJC CM BDGC, CM BDGC, CM BDGC, CM CM, URC BDGC, CM BDGC, CM IAVH, CM IAVH CM IAVH, CM CM CM CM, FVMC CM CM, URCA CM URC IAVH, CM CAM IAVH, CM IAVH CM CM BDGC, CM IAVH BDGC IAVH, CM IAVH

Bolivia, Colombia Co1ombia Co1ombia Colombia Colombia Bolivia Colombia Colombia Mexico Mexico

2 12 1 1 2 2 4 2 2 2

1 4 1 0

0 0 1 1 0 1

IAVH CM IAVH IAVH IAVH CM IAVH, CM CM BDGC, CM BDGC, CM

Colombia Ecuador Haiti Dominican Republic Brazil Argentina Uruguay Argentina Venezuela Bolivia Colombia Venezuela Colombia, Bolivia, Argentina Guyana

2 1 1 2 10 2 1 2 1 2 8 1 3

6 0 0 1 3 1 0 0 1 1 1 1 1

CM, IAVH CM BDGC CM, SAM CM CM URC CM CM CM CM, EVMC BDGC CM, IAVH

2

0

CM

Canthon Boreocanthon

Canthon

Francmonrosia

Glaphyrocanthon

Goniocanthon Nesocanthon Peltecanthon Pseudepilissus Trichocanthon Incertae sedis

C. bicolor Laporte


65

Appendix 1 (continued) Species

Country

6

0

Collection

C. balteatus Redtenbacher C. perseverans Matthews C. triangularis (Drury) C. hartmanni Howden & Gill C. unicolor Blanchard C. sp. (Unicolor group)

Ecuador Granada Colombia Panama Brazil Brazil

1 2 6 0 1 2

1 2 2 1 0 1

CM CM CM, IAVH CM FVMC CM

Anisocanthon

A. villosus (Harold)

Colombia

1

1

IAVH

Cryptocanthon

C. parvus Howden Cryptocanthon sp.

Colombia Colombia

1 1

0

1

CM CM

C. gomezi (Halffter & Martinez)

Venezuela

1

0

ALC

Colombia Co1ombia Colombia Colombia Colombia Colombia Brazil USA Colombia Brazil Brazil Colombia

2 2 1 2 0 4 1 3 1 1 1

0 0 0 0

Parahy boma Rubrohyboma Telhyboma

D. hypponum (Buquet) D. mexicanurn (Burmeister) D. spl. (mexicanum group) D. sp2. (mexicanum group) D. aequinoctiale (Buquet) D. parile Bates D. brasiliense (Castalnau) D. gibbosum (Fabricius) D. orbignyi (Blanchard) D. furcatum (Castalanau) D. rubripenne (Gory) D. orbiculare Lansberge

1

3 1 1 0 0 0 0

IAVH, CM CM IAVH IAVH CM CM CM CM CM FVMC, CM CM CM

Hansreia

H. afinis (Fabricius)

Guyana

3

2

CM, NHML

Holocanthon

H. mateui Martinez & Pereira

Brazil

1

0

CM

M. astyanax columbica (Harold)

2

1

1 1

M. puncticollis (Blanchard)

Colombia Argentina Brazil

1

0

IAVH, CM CM, URCA UJC, URCA

M. punctatostriata (Blanchard) M. bicolor (Guerin, 1840)

Bolivia Uruguay

1 2

1 1

ALC CM

Melanocanthon

M.bispinatus (Robinson)

USA

2

2

CM

Scybalocanthon

S. trimaculatus (Schmidt) S.moniliatus (Bates) S.pygidiulis (Harold) S.sexpilotus (GuCrin)

1 1 2 0 1

1 0

s. sp.

Colombia Costa Rica Venezuela Colombia Co1ombia

1

IAVH CM CM IAVH IAVH

S. bridarollii (Martinez) S.forveiventris Schmidt

Colombia Brazil

2 1

1 0

CM FVMC

Genera (subgenera)

Canthonella Deltochilum Calhyboma

Deltohyboma Euhyboma Hybomidium

Malagoniella

M.magnifica Balthasar Megathopa

Sylvicanthon

1

1 1

Canthonella gomezi Cryptocanthon sp Malagoniella astyanax Megathopa punctatostriata Deltochilum gibbosum Scybalocanthon pygidialis Scybalocanthon moniliatus Scybalocanthon trimaculatus Silvicanthon bridarollii Anisocanthon villosus Hansreia aflnis Melanocanthon bkpinatus Canfhon septemmaculatus Canthon quinquemaculatus Canthon triangularis Canthon tetraodon Canthon dives Canthon latipes Canthon rutilans Canthon aberrans Canthon chalcites Canthon imitator Canthon pilularius Canthon indigaceus Canthon cyanellus Canthon praticola Canthon ebenus Canthon lecontei Canthon rubrescens Canthon luteicollis Canthon femortalis Canthon angustatus Canthon politus Canthon srnaragdulus Canthon staigi Canthon bicolor Canthon tibiale Canthon violaceus Canthon sordidus

01- -10011 1000-0- 1000 000111-1010 0120012030000-00-- - - - - - - - - - 0 0 0 0 0 0 0 3 0 0 0 2 0 0 0 0 1 1 1 1 0 0 0 0 01--10111 0000-0-102-000011-1010 01200100101010 03-----0 0 1 0 0 0 0 000000031002000011120110 0 0 0 1 0 0 0 1 1 1 1 1 1 3 11 0 1 0 0 1 2 3 0 1 0 1 0 1 1 1 0 1 2 0 0 1 1 0 2 2 0 0 0 - 0 2 - - - - - 0 0 --0 0 0 000111030002000001110000 0 0 0 1 0 0 0 1 1 1 1 1 1 3 11 0 1 0 0 1 2 1 0 1 0 0 0 1 1 1 0 1 2 0 0 1 0 0 2 2 0 0 0 - 0 2 - - - - - 0 0 --0 0 0 000111030002000001110000 0 0 1 - 1 0 0 1 0 0 1 0 1 2 11 0 1 0 0 1 2 3 0 1 1 - 0 0 1 1 0 1 2 0 0 1 0 1 1 0 0 0 1 1 0 3 - - - - - 0 0 --0 0 0 000100130011010000100110 000 110011 11113 10 0110 023111-1110 0010010101000-010 1 3 0 1 0 0 1 1 0 0 0 000101131101121011110000 000 1 1 0 0 1 1 11113 10 0110 023111-1110 01000101000011 010 1 3 0 1 0 0 1 1 0 0 0 000101131101121011110000 000 1 1 0 0 1 1 11113 10 0110 023111-1110 01000101000011 010 1 3 0 1 0 0 1 1 0 0 0 000101131101121011110000 0 0 0 1 1 0 1 0 - 1 1 1 1 3 11 0 1 0 0 0 0 0 1 1 1 - 1 1 0 - 1 0 1 0 0 1 0 0 0 0 1 0 2 - 0 1 0 0 0 0 1 0 0 1 0 0 0 0 000010130001010011110000 0 0 0 1 1 0 0 1 1 1 1 1 1 4 11 0 1 1 1 0 1 0 0 1 1 - 0 1 0 - 0 1 1 0 0 1 0 0 0 0 0 0 1 1 011 1 2 0 1 0 0 1 0 0 0 0 000000130002000010111100 0 0 0 1 1 0 0 0 - 1 1 1 1 1 1 0 0 1 1 2 0 2 1 0 0 0 1 1111 0 1 0 0 0 1 0 0 1 0 0 0 1 1 111 2 3 0 1 1 0 1 0 0 0 0 0 0 0 1 1 0 1 3 0 0 0 2 0 0 0 0 1 1 0 2 0 0 0 0 1 0 0 0 0 0 1 1 1 1 1 0 1 4 11 0 1 1 2 0 1 3 0 0 0 0 0 1 0 - 1 1 2 0 0 1 0 0 0 0 0 0 1 0 0 1 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 2 0 0 0 0 1 0 1 1 1 0 0 0 0 1 1 0 0 0 0 1 0 1 1 1 1 3 11 0 1 1 1 0 2 3 0 1 0 1 1 1 0 - 1 1 1 0 0 1 0 0 0 0 0 0 1 2 0 1 0 1 2 0 1 0 0 0 0 0 0 0 0 0 0 1 1 0 1 2 0 0 0 2 0 0 0 1 1 1 1 1 0 0 0 1 1 0 0 1 1 0 0 1 1 1 1 1 1 3 11 0 1 1 1 0 2 2 0 1 0 0 1 1 0 - 0 1 1 0 0 1 0 0 0 0 0 0 1 1 0 1 0 1 3 0 1 0 1 1 0 0 0 0 0 0 0 1 1 0 1 2 0 0 0 2 0 0 0 0 1 1 1 1 0 0 0 1 0 0 1 - 1 0 0 1 1 1 1 1 1 4 11 0 1 1 1 0 2 3 1 0 1 - 1 1 0 - 1 1 1 0 0 0 0 0 0 0 0 0 1 1 010 1 2 0 1 0 0 0 0 0 0 0 000100120002000111110001 1 0 0 0 0 0 0 1 1 1 1 1 1 4 11 0 1 1 1 0 2 2 0 1 1 - 1 1 0 - 0 1 1 0 2 1 0 0 0 1 0 0 2 - 0 1 0 1 0 2 0 0 0 0 0 2 1 0 022011110001000010110000 1 0 0 0 0 0 0 1 1 1 1 1 1 4 11 0 1 1 1 0 2 2 0 1 1 - 1 1 0 - 0 1 1 0 2 1 0 0 0 1 0 0 2 - 0 1 0 1 0 1 0 0 0 0 0 2 1 0 022011110001000010110000 1 0 1 0 0 0 0 0 2 1 0 012011110001000010110000 0 0 0 0 0 1 0 1 1 1 1 1 1 4 11 0 1 1 1 0 1 1 0 1 1 - 1 1 0 - 0 1 1 0 1 1 0 0 0 1 0 0 2 - 0 1 0 0 0 0 0 0 1 0 1 1 1 1 1 1 4 11 0 1 1 1 0 1 1 0 1 1 - 1 1 0 - 0 1 1 0 1 1 0 0 0 1 0 0 2 - 0 1 0 1 0 1 0 0 0 0 0 2 1 0 011011110001000010110000 0 0 0 1 1 0 0 1 1 1 1 1 1 3 11 0 1 1 2 0 2 1 0 1 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 0 2 - 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 1 0 0 0 2 0 0 0 0 1 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 1 1 1 0 1 4 11 0 1 1 2 0 2 3 0 1 0 0 1 1 0 - 0 1 0 1 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 2 0 0 0 0 1 0 0 1 1 0 0 0 0 1 0 0 0 0 0 1 1 1 1 0 1 4 11 0 1 1 2 0 2 3 0 1 0 0 1 1 0 - 0 1 0 1 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 1 0 1 0 0 1 0 0 0 0 0 1 1 1 1 1 0 0 0 2 0 0 0 0 1 0 0 1 1 0 0 0 0 1 0 0 0 0 0 1 1 1 1 0 1 4 11 0 1 1 2 0 2 3 0 1 0 0 1 1 0 - 0 1 0 1 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 1 0 1 0 0 1 0 0 0 0 0 0 1 1 1 1 0 0 0 2 0 0 0 0 1 0 0 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 4 11 0 1 1 2 0 2 3 0 1 0 0 1 1 0 - 1 1 1 1 0 1 0 0 0 1 0 0 1 0 0 1 0 1 3 0 1 0 1 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 2 0 0 0 0 1 0 1 1 0 0 0 0 1 1 0 1 0 0 0 1 1 1 1 1 1 2 11 0 1 1 1 0 2 2 0 1 0 0 1 1 0 - 1 1 1 0 0 0 0 0 0 0 0 0 1 2 0 1 0 0 3 0 1 0 1 0 0 0 0 0 0 0 0 1 1 0 1 3 0 0 0 2 0 0 0 1 1 1 1 1 0 0 0 1 100 0 00011 11014 11 0112 0120000 010-11100100100011 010 1 0 0 0 0 0 0 0 0 0 0 000010110102000010111000 1 0 0 0 0 1 0 1 1 1 1 0 1 4 11 0 1 1 2 0 1 2 0 0 0 0 0 1 0 - 1 1 1 0 0 1 0 0 1 0 0 0 1 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 1 0 1 0 2 0 0 0 0 1 0 1 1 1 0 0 0 1 0 0 0 0 1 0 1 1 1 1 0 1 4 11 0 1 1 2 0 1 2 0 0 0 0 0 1 0 - 1 1 1 0 0 1 0 0 1 0 0 0 1 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 1 0 1 0 2 0 0 0 0 1 0 1 1 1 0 0 0 1 0 0 1 1 0 0 1 1 1 1 0 1 4 11 0 1 1 1 0 1 0 0 1 1 - 1 1 0 - 0 1 0 0 0 1 1 0 0 0 0 0 2 - 0 1 0 1 2 0 1 0 0 1 0 0 0 1100110120002000011110000 1 0 0 1 1 0 1 1 1 1 1 1 1 4 11 0 1 1 1 0 1 0 0 1 1 - 1 1 0 - 0 1 0 0 0 1 1 0 0 0 0 0 1 0 010 1 2 0 1 0 0 1 0 0 0 1100110120002000111110000 1 0 0 3 1 0 0 1 1 1 1 0 1 4 11 0 1 1 1 0 1 0 0 1 1 - 1 1 0 - 0 1 0 0 0 1 1 0 0 0 0 0 1 1 010 1 2 0 1 0 0 1 0 0 0 1100110120002000111110000 1 0 0 1 1 0 0 1 1 1 1 0 1 4 11 0 1 1 1 0 1 0 0 1 1 - 1 1 0 - 1 1 0 0 0 1 1 0 0 0 0 0 2 - 0 1 0 1 2 0 1 0 0 1 0 0 0 1100110120002000111110000 0 0 1 111111 1 1 0 1 3 11 0 1 0 0 0 1 1 0 1 1 - 1 1 0 - 0 1 1 0 0 0 0 0 0 0 1 0 2 - 0 1 0 1 3 0 0 0 0 1 0 0 0 0 000110120102000011110000 0 0 0 1 1 0 0 1 1 1 1 1 1 2 11 0 1 1 1 0 2 3 0 1 0 0 1 1 0 - 0 1 0 0 0 1 0 0 0 0 0 1 1 1 1 3 - - - 0 -0 0 0 0 0 0 0 000010130002000001110000 0 0 0 1 1 0 0 0 1 1 1 1 1 2 11 0 1 1 1 0 2 1 0 1 1 - 1 1 0 - 0 1 0 0 0 1 0 0 0 0 0 1 2 2 111 2 3 0 1 1 0 1 0 0 0 0 0 0 0 0 1 0 0 1 0 1 0 2 0 0 0 0 0 0 1 1 0 0 0 0 0 0 1 1 1 0 0 0 1 1 1 1 1 2 11 0 1 0 0 0 2 2 1 1 1 - 1 1 0 - 0 1 0 0 0 1 0 0 0 0 0 1 2 2 111 2 3 0 1 1 0 1 0 0 0 0 000010010102000000110000 0 0 0 0 1 0 0 1 0 1 1 0 1 4 11 0 1 1 2 0 1 2 0 1 0 0 1 1 1 1 0 1 2 0 0 1 0 0 0 0 0 0 1 1 0 1 0 1 1 0 1 0 0 1 0 0 0 0 0 0 0 1 0 0 1 0 0 0 1 2 0 0 0 0 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 4 11 0 1 1 1 0 2 3 0 1 0 0 1 1 0 - 0 1 2 0 0 1 0 0 0 0 0 0 2 - 0 1 1 2 3 0 1 1 0 1 0 0 0 0 0 0 0 1 1 1 1 2 0 0 0 2 0 0 0 0 1 0 1 1 0 0 0 1 000 1 1 0 0 1 1 11113 1 1 0 1 1 1 0 2 2 1 0 1 - 1 1 0 - 1 1 1 0 0 1 0 0 0 0 0 0 1 1 010 1 3 0 1 0 0 0 1 0 0 0 000100121002121010120100

11111 11 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 8 8 8 8 123 4 56789 01234 56 7890 1234567 8901 23456789012345 678 9 0 1 2 3 4 5 6 7 8 9 012345678901234567890123

Appendix 2 Data matrix for 39 taxa including Canthon and other genera of new world Canthonini used in the cladistic analysis, (for description of characters states see Appendix 3).


67

Appendix 3 Morphological characters used in the cladistic analysis. 0 = presumed plesiomorphic, state; 1, 2, 3, 4 = apomorphic states.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58.

Dorsal clypeal teeth number: (0) two (Fig. 9); (1)four (Fig. 15); Anterior cephalic border: (0) with setae (Fig. 13); (1) glabrous (Fig. 10); Anterior cephalic border: (0) with setae on a keel (Fig.17); (1) without setae on a keel (Fig. 12); Keel with setae: (0) entire (running along the clypeus) (Fig. 17); (1) just at the base of the teeth (Fig. 18); Clypeus: (0) wrinkled; (1) smooth, not wrinkled; Gena: (0) entire (Fig. 12); (1) divided (Fig. 16); Ventral, longitudinal carina of the clypeus: (0) absent (Fig. 26); (1) present (Fig. 25); Medial process of the epipharynx: (0) not reaching the anterior border (Fig. 43); (1) reaching the anterior border (Fig. 44); Medial process of the epipharynx: (0) surpassing the anterior border (Fig. 45); (1) not surpassing the anterior border (Fig. 44); Medial process of the epipharynx: (0) with a chitinous overgrow; (1) without a chitinous overgrow; Medial process of the epipharynx at the transverse suture: (0) oblique; (1) parallel; Hairs on the anterior border of the epipharynx: (0) shorter (Fig. 45); (1) longer (Fig. 43); Internal lateral comb of the epipharynx: (0) incomplete (Fig. 36); (1) complete (Fig. 34); Lateral combs of the epipharynx: (0) fused (Fig. 42); (1) not fused (Fig. 41); Cavities on dorsal side of the proximal epipharynx: (0) absent; (1) present (Fig. 35); Epipharynx cavities: (0) reduced; (1) ample (Fig. 35); Posterior end of the medial process: (0) not diamond-shaped; (1) diamond-shaped; Posterior end of the medial process: (0) without lateral arms; (1) with lateral arms; Eyes dorsally: (0) wide (Fig. 27); (1) narrow (Fig. 28); (2) not visible; Eyes dorsally: (0) not banded (Fig. 27); (1) surrounded by a thin band (Fig. 31); ( 2 ) surrounded by a thick band (Fig. 32); Anterior border of the basisternum of prosternum: (0) without indentation; (1) with indentation; Proepimeron: (0) deeply excavated (Fig. 75); (1) slightly excavated (Fig. 74); (2) not excavated (Fig. 85); Proepisternal keel: (0) complete (Fig. 70); (1) incomplete (Fig. 78); (2) insinuated (Fig. 76); (3) absent (Fig. 78); Proepimeron: (0) with setae (Fig. 82); (1) glabrous (Fig. 83); Proepisternum: (0) with setae (Fig. 79); (1) glabrous (Fig. 84); Prosternum: (0) with a row of setae running parallel to the lateral border of the pronotum (Fig. 80); (1) without a row of setae (Fig. 83); Row of setae of the prosternum: (0) covering proepimeron and proepisternum (Fig. 80); (1) covering only the proepimeron (Fig. 84); (2) covering only the proepisternum (Fig. 81); Mesocoxal cavities: (0) oblique: (1) parallel; Mesosternum: (0) elongated (1) reduced; Anterior border of the mesosternum: (0) complete; (1) interrupted in the middle; Anterior border of the mesosternum: (0) curved; (1) straight; Medial part of the anterior border of the mesosternum: (0) forming a sharp tip; (1) straight; Parameres of the aedeagus: (0) asymmetric; (1) symmetric; Posterior border of the parameres: (0) notched (Fig. 135); (1) divided (Fig. 137); (2) with pointed tip (Fig. 134); Parameres of the aedeagus: (0) without lateral projection (Fig. 135); (1) with lateral projection (Fig. 137); Parameres of the aedeagus: (0) without arch; (1) forming a sinuate arch (2) forming a deep arch Medial lobe and parameres of the aedeagus: (0) forming a right angle; (1) not forming a right angle; Parameres of the aedeagus in relation of the medial lobe: (0) larger; (1) the same length (2) shorter; (3) reduced; Internal sac of the aedeagus: (0) straight; (1) with a lateral fold; Number of sclerites of the internal sac: (0) more than three; (1) three; (2) two; (3) one; Scale area of the internal sac: (0) absent; (1) reduced; (2) large; Half-moon shaped sclerite of the internal sac: (0) absent; (1) present; Boomerang-shaped sclerite: (0) absent; (1) present; Elongated sclerite: (0) absent; (1)with filament; without filament; Elongated sclerite: (0) with short filament (Fig. 147); (1) with elongated filament (Fig. 147); (2) with very long filament (Fig. 148); Small sclerite over the elongated sclerite: (0) absent; (1) present; Internal sac: (0) without circular sclerite; (1) with circular sclerite Cunthon type I (Fig. 139); (2) with circular sclerite Mulugoniellu type (Fig. 172); (3) with circular sclerite Orbygnyi type (Fig. 166); (4) with circular sclerite Mexican group type (Fig. 164); Handle of circular sclerite type I: (0) long (Fig. 139); (1) short (Fig. 143); Ring of circular sclerite type I: (0) thickened (Fig. 139); (1) partially thickened (Fig. 141); (2) thinner (Fig. 143); Ring of circular sclerite type I: (0) with overgrowth, sharp protuberance (Fig. 150); (1) with overgrowth, blunt protuberance (Fig. 159); (2) without protuberance (Fig. 141); Handle of circular sclerite type I: (0) fused to the ring (Fig. 168); (1) partially fused (Fig. 167); (2) separated from the ring (Fig. 144); Handle of circular sclerite type I: (0) partially surrounding the ring; (1) not surrounding the ring; Circular sclerite type I: (0) with oval ring (Fig. 139); (1) with rounded ring (Fig. 143); Distal end of the handle of the circular sclerite type I: (0) not bend up (Fig. 169); (1) bend up (Fig. 142); Handle of the circular sclerite type I: (0) with medial process (Fig. 170); (1) without medial process (Fig. 171); Handle of the circular sclerite type I: (0) not thickened on the base; (1) thickened on the base; Lateral plate sclerite of the internal sac: (0) without process in the internal edge; (1) with proximal process; (2) with distal process (Fig. 149); Fourth sclerite of the internal sac: (0) separated and laterally located to the lateral plate sclerite; (1) closest and distally located to the lateral plate sclerite;

68


Appendix 3 (continued) 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81. 82. 83.

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Lateral plate sclerite: (0) not expanded; (1) expanded basally; Lateral plate sclerite: (0) not as a big concave plate (Fig. 155); (1) as a concave plate (Fig. 158); Fore femur: (0) not excavated distally; (1) moderately excavated; (2) deeply excavated Fore femur in ventral face: (0) without tooth (Fig. 92); (1) with a small tooth (2) with a big tooth (Fig. 91); Anterior fore tibiae truncation: (0) straight (Fig. 97); (1) oblique (Fig. 98); Sexual dimorphism in fore tibiae: (0) absent; (1) present; Ventral face of the middle femur: (0) without apical setae; (1) with apical setae (Fig. 103); External row of setae of the dorsal face of the middle tibiae: (0) incomplete (Fig. 110); (1) complete (Fig. 112); Carina on dorsal face of the meddle tibiae: (0) complete (Fig. 111); (1) incomplete (Fig. 108); (2) insinuated (Fig. 116); (3) absent (Fig. 117); Internal face of medial tibiae: (0) glabrous; (1) with setae in the middle; Ventral face of the posterior femur: (0) with margin on the anterior border; (1) without margin; Sexual dimorphism in posterior tibiae: (0) absent; (1) present; First segmental tarsi in relation to the second: (0) longer; (1) shorter; (2) the same length; Shape of the middle and hind tarsomeres: (0) triangular (Fig. 118); (1) rectangular (Fig. 119); Second tarsomere on hind leg: (0) as the first one (Fig. 118); (2) longer; (3) twice longer (Fig. 119); Fifth posterior tarsi: (0) not elongated (1) elongated Medial and posterior femoral color: (0) like body; (1) contrasting; Humeral striae: (0) keeled (1) not keeled; Area humeral of elytra: (0) with tubercles; (1) without tubercles; Position of the lateral border of the elytra: (0) dorsum-laterak (1) lateral-ventral; Lateral border of the elytra: deeply curved (1) sinuate; (2) straight; Surface of tegument of the elytral disc: (0) no granulate (Fig. 124); (1) granulate (Fig. 123); Interstriae: (0) without row of setae; (1) with row of setae; Lateral border of the elytra: (0) without keel; (1) with marked keel; Pygidium color: (0) similar with body; (1) contrasting;

Appendix 4 List of abbreviations used in the figures. an af br ca cc cl cls clse dP ebr eP eY gn gl ha hap hde hPe Lc mn mP

antennae apical fringe brushes of internal sac canthus coxal cavity clypeus clypeal suture clypeal setae distal process external border of ring proepimeron eye gena gula handle handle process distal end of handle proximal end of handle lateral combs mentum medial process

prosternum proepisternal keel proepisternum ring sclerite temones tormae transverse suture