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The Coleoptera of the Seychelles islands Edited by Justin Gerlach
Sofia–Moscow 2009
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Seychelles Fauna Monographs The Indian Ocean Biodiversity Assessment 2000-2005 reviewed the biogeography of the Seychelles islands through systematic collecting of all taxonomic groups. Biodiversity collecting for this assessment started in 2000 under a Memorandum of Understanding with the Seychelles government with taxonomic support from 87 expert taxonomists in 20 countries. These taxonomists reported the identification of a large number of previously undescribed species and the material initiated taxonomic revisions of most of the groups concerned. These revisions are being published in widely dispersed academic journals, most of which are not available in Seychelles. The only comprehensive taxonomic treatments available cover dicotyledon plants and vertebrates. The information generated by the project has been collated into a monographic series on the Seychelles fauna. The aim of these monographs is to disseminate taxonomic information in a form that can be easily utilised by future workers in the region and by conservationists and researchers in Seychelles. This high quality biodiversity information is essential for future sustainable biodiversity management. Further details of the Indian Ocean Biodiversity Assessment can be found on the Nature Protection Trust of Seychelles web-site: http://islandbiodiversity.com.
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First published 2009 ISBN 978-954-642-498-3 (paperback) ISBN 978-954-642-499-0 (e-book) Pensoft Series Faunistica No @@ ISSN 1312-0174
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Family PHALACRIDAE The shining mold beetles Matthew L. Gimmel Introduction and biology With 52 genera and over 600 species, the Phalacridae is a moderately diverse family of Coleoptera. The family is distributed nearly worldwide, with the highest concentration of species in tropical regions. They are generally easy to recognize by their small size (1-5mm, Seychelles species 1-2.5mm), convex and glabrous dorsal surface, more or less vertically explanate lateral margins of the elytra and pronotum, globular front coxae, and distinct 3-segmented antennal club. The only prior treatment of the Seychelles fauna was the outstanding work of Scott (1922), but most of his types have not been compared with Malagasy and nearby continental species by any subsequent workers and it is unknown whether any of the Seychelles species is truly endemic. Unfortunately in most cases examination of male genitalia is necessary for reliable species-level identification. There are likely additional species of the family waiting to be discovered on the islands. The author is currently performing a world-level generic revision of the family, and some Seychelles species will likely receive generic reassignments. Nothing has been recorded about the biology of the Seychelles species, though related taxa are thought to be surface mold grazers on dry vegetation (dead hanging leaves, grass tussocks, legume pods, etc.) as larvae and probably also as adults. Sweeping and beating of these habitats should produce adults in moderate numbers. Key to Seychelles species 1. Mesoventrite a large sclerite between middle coxae, longer than wide (Scott 1922, Fig. 39); hind tarsi similar to other tarsi (Scott 1922, Fig. 5d, e); body broadly oval (length not much greater than width) (subfamily Phaenocephalinae) Phalacratomus exiguus Mesoventrite concealed or forming only a narrow, horizontal sclerite between middle coxae (Scott 1922, Fig. 34 & 36); hind tarsi with one or more segments distinctly longer than corresponding segments on other tarsi (Scott 1922, Fig. 1c, d, 2b-d, 3d-f ); body more elongate (distinctly longer than wide) (subfamily Phalacrinae) 2 2. Elytron with nine regular striae Biophytus sp. Elytron with one sutural stria (and sometimes additional, very faintly indicated striae) 3 3. First segment of hind tarsus greatly elongate, longer than remaining segments combined (Scott 1922, Fig. 2d); hind tibial spurs long, much longer than crown of spines at apex of tibia; elytra testaceous, often with black maculations Augasmus thoracicus First segment of hind tarsus shorter than second segment (Scott 1922, Fig. 1d, 3e, f, 4b); hind tibial spurs short, hardly longer than crown of spines at apex of tibia; elytra unicolorous, dark 4 4. Coxal lines of metaventrite broadly rounded behind (Scott 1922, Fig. 36) 5 Coxal lines of metaventrite angularly acuminate behind (Scott 1922, Fig. 34) Stilbus angulicaput 5. Hind tarsi with second segment more than twice as long as first segment (Scott 1922, Fig. 4b); 1.5-1.8mm Nesiotus similis Hind tarsi with second segment less than twice as long as first segment (Scott 1922, Fig. 3e, f ); 1.3-1.5mm Tinodemus tropicus
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Subfamily PHAENOCEPHALINAE Phalacratomus exiguus Scott, 1922 Phalacratomus exiguus Scott 1922: 242. Distribution. Endemic. Mahé (Morne Blanc, Morne Pilot, Cascade, Mare aux Cochons 1908-9), Silhouette (Mt. Pot a Eau, Mare aux Cochons and above 1908). Description. More globular in shape than other Seychelles phalacrids. Brownish-black with head, pronotum and tip of elytra sometimes yellowish-brown; underside paler; appendages yellowish, with antennal club usually darker. Easily recognized by the comparatively large mesoventrite and short hind tarsi. Length 0.9-1.2mm. Notes. A monotypic, endemic genus, and the only Seychellois representative of the subfamily Phaenocephalinae, but not sufficiently distinguishable from Phaenocephalus Wollaston. Phalacratomus will probably be synonymized with that genus in a forthcoming publication. Subfamily PHALACRINAE Tinodemus tropicus (Scott, 1922) Nesiotus tropicus Scott 1922: 237. Tinodemus tropicus: Švec 2002: 236. Distribution. Mahé (Morne Blanc, above Pot Glaud, Cascade, Anse aux Pins / Anse Royale 1892, 1908-9), Round (1908), Long (1908), Silhouette (Mt. Pot a Eau, Mare aux Cochons 1908), Praslin (Vallee de Mai 1908). Description. Uniformly black above; underside reddish, appendages reddish to yellowish. This species and Nesiotus similis are easily separated from other Seychelles species by the arcuate coxal lines on the metaventrite. It differs from N. similis in having a relatively shorter second hind tarsal segment. Length 1.3-1.5mm. Notes. Scott provisionally referred specimens from Madagascar and Réunion to this species. This species will soon receive a different generic assignment, as true Tinodemus are exclusively New World taxa. Nesiotus similis Scott, 1922 Nesiotus similis Scott 1922: 239. Distribution. Mahé (Morne Blanc, above Pot Glaud, Cascade, Anse aux Pins / Anse Royale 1892, 1908-9), Round (1908), Long (1908), Silhouette (Mt. Pot a Eau, Mare aux Cochons 1908), Praslin (Vallee de Mai 1908). Description. Similar to Tinodemus tropicus but with a relatively longer second hind tarsal segment. Length 1.5-1.8mm. Notes. Scott indicated that a few Rodrigues and Madagascar specimens may belong to this species. The status of the genus Nesiotus Guillebeau is questionable. Stilbus angulicaput (Scott, 1922) Stilboides angulicaput Scott 1922: 233. Stilbus angulicaput: Švec 2003: 108. Distribution. Endemic. Silhouette (above Mare aux Cochons 1908). Description. Uniformly black above; underside and appendages dark reddish. Easily separated from all other Seychelles species by the acutely pointed coxal lines on the metaventrite. Length 1.6 mm. Notes. Originally described in the Guillebeau genus Stilboides, which was later synonymized with Stilbus Seidlitz.
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Augasmus thoracicus (Fleutiaux, 1887) Olibrus thoracicus Fleutiaux 1887: 61. Heterolitus thoracicus: Guillebeau 1893: 376. Parischius seychellensis Scott 1922: 235. Augasmus thoracicus: Lyubarsky 1994: 51. Distribution. Mahé (Cascade, Mare aux Cochons 1908-9), Silhouette (Mt. Pot a Eau, above Mare aux Cochons 1908), Praslin (Vallee de Mai 1908). Description. Highly variable in colouration and patterning; usually with ferrugineous ground colour, with or without black markings in the form of a diamond centered on the elytral suture, or a black basal band across elytra, sometimes only one is present, and sometimes both are expanded such that the greater part of the elytra is black except for a pale basal and pale apical spot. Distinctive for its elongate first hind tarsal segment. Length 1.7-2.0mm. Notes. Originally described as an endemic, Parischius seychellensis, it is now known to be synonymous with an abundant and widely distributed species in the Old World tropics. Biophytus sp. Distribution. Aldabra (Ile Picard Settlement, 1986, D. Adamski). Description. Pale testaceous throughout, and easily recognized by its nine regular elytral striae. The first hind tarsal segment is about as long as the remaining segments combined. Length 2.1 mm. Notes. The specific identity of the single collected specimen is unknown, but it is likely conspecific with one of the Malagasy or mainland African forms. The genus is endemic to the Afrotropical region. References Fleutiaux, E. 1887. Descriptions de Coléoptères nouveaux de l’Annam. Ann. Soc. Entomol. France 56: 59-68. Guillebeau, F. 1893. Contributions a la faune Indo-Chinoise. Phalacridae. Ann. Soc. Entomol. France 62: 374-379. Lyubarsky, G.Yu. 1994. New and little-known Phalacridae (Coleoptera Clavicornia) from the Oriental region. Russ. Entomol. Journ. 3(1-2): 49-59. Scott, H. 1922. No. 4. Coleoptera: Scydmaenidae, Scaphidiidae, Phalacridae, Cucujidae (supplement), Lathridiidae, Mycetophagidae (including Propalticus), Bostrichidae, Lyctidae. The Percy Sladen Trust Expedition to the Indian Ocean in 1905 under the leadership of Mr. J. Stanley Gardner, M.A. Vol. 7. Trans. Linn. Soc. Lond. (2 Zool.) 18: 195-260, pl. 19-22. Švec, Z. 2002. Revision of the African species of the genus Tinodemus Guillebeau (Coleoptera, Phalacridae). Results of the entomological expeditions of the Museum of Natural History, Berlin to Africa. 76th contribution. Mitt. Mus. Naturk. Berlin Zool. Reihe 78(2): 217-256. Švec, Z. 2003. A review of the genera Stilbus Seidlitz, 1872, Podocesus Guillebeau, 1894 and Entomocnemus Guillebeau, 1894 from Africa, Madagascar and the Seychelles (Coleoptera, Phalacridae). Entomolog. Basil. 25: 99-133.
