View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by University of Fukui Repository Japanese Journal of Systematic Entomology, 22 (1): 131–133. May 30, 2016. Taxonomic Report of the Genus Peltocercyon (Coleoptera: Hydrophilidae: Sphaeridiinae) Hideto HOSHINA Faculty of Education, Fukui University, Fukui City, 910–8507 Japan Abstract A Japanese hydrophilid beetle, Cercyon subopacipennis Nakane, 1965, is transferred to the genus Peltocercyon d’Or- chymont, 1925. Peltocercyon is recorded for the first time from the palaearctic region. Some figures of important morphological features of P. subopacipennis are given. Introduction shining. Body 2.3–2.6 mm in length, about 1.7 times as long as The genus Peltocercyon was established by d’Orchymont wide (Fig. 1), almost glabrous on dorsum; head smooth on (1925) based on one species, P. coomani d’Orchymont, 1925 dorsum, minutely and densely punctate (Fig. 1); pronotum (monotypy) and belongs to the tribe Megasternini of the smooth on dorsum and densely punctate; punctures of subfamily Sphaeridiinae of the family Hydrophilidae. Later, pronotum larger than those of head (Fig. 1); elytra widest at Hansen (1991) transferred Cercyon lunulatus Gemminger & about basal 1/4 (Fig. 1); elytral series 3 and 4 curved to the Harold, 1868 to Peltocercyon. Other species of the genus have outside from base towards about basal 2/5 (Fig. 1); intervals not been discovered until now. In addition, those two species between elytral series sparsely and minutely punctate and are distributed in only the Oriental region (Hansen, 1999; strongly microreticulate (Fig. 2); punctures on intervals Short & Fikáček, 2011). between elytral series minuter than serial punctures (Fig. Recently, I had an opportunity to examine holotype and 2); hind wings normal; prosternum with a distinct median three paratypes of a Japanese hydrophilid beetle, Cercyon longitudinal carina; preepisternal plate of mesothorax subopacipennis Nakane, 1965. My careful examination widest at about apical 1/3 and distinctly punctate (Fig. 3); showed that C. subopacipennis was a member of Peltocercyon. metaventrite microreticulate and almost impunctate except for Therefore, I transfer that species to Peltocercyon in this paper. a pentagonal median portion; pentagonal median portion of As a result, Peltocercyon is recorded for the first time from the metaventrite smooth and minutely but distinctly punctate (Fig. palaearctic region and P. subopacipennis (Nakane) becomes 4); anterolateral ridge distinct, elongating to inner margins third species of the genus. of anepisternum 3, posteriorly bent there, and approaching All type specimens used in this study are preserved in the posterior margin of metaventrite (Fig. 4); femoral lines distinct collection of Hokkaido University Museum, Sapporo, Japan and long, and reaching anterior corners of metaventrite (Fig. (HUMS). The morphological terminology follows Hansen 4); transverse suture distinct and elongating along posterior (1991), Komarek (2004), and Fikáček et al. (2009). margin of metaventrite (Fig. 4); abdominal ventrite 1 with a Before going further, I would like to express my hearty distinct median carina. thanks to Dr. Masahiro Ôhara (Hokkaido University Museum, Male. Sternite 9 as shown in Fig. 5; median lobe of Sapporo, Japan) for giving me an opportunity to examine aedeagus bluntly pointed apically (Fig. 6); length of paramere type specimens. I am deeply indebted to Dr. Martin Fikáček about as long as that of phallobase (Figs. 6 and 7). (National Museum, Czech Republic) and Dr. Sergey K. Distribution. Japan: Honshu (Nagano Pref.). Ryndevich (Baranovichi State University, Belarus) for their Specimens examined. Holotype: ♂, Mt. Jônen, Nagano kind advice. Pref., Honshu, 6. x. 1960, K. Kamimura leg. (HUMS). Paratypes: 3 ♀, same data as holotype except for the date, 2. Peltocercyon subopacipennis (Nakane, 1965) vi. 1960, 15. ix. 1960, 6. x. 1960, respectively (HUMS). comb. nov. Notes. Hansen (1991) mentioned that the genus Cercyon [Japanese name: Ibushi-nise-keshigamushi] Leach, 1817 has the metaventrite without anterolateral ridges (Figs. 1–7) in the generic diagnosis of the family Hydrophilidae. In contrast, Ryndevich (2006) indicated subgenera Conocercyon Cercyon subopacipennis Nakane, 1965: 53; Hansen, 1999: Hebauer, 2003 of the genus Cercyon, has metaventrite with 290; Hansen, 2004: 64. anterolateral ridges. In Cercyon, femoral lines of metaventrites are absent Diagnosis. Male and female. Coloration. Dorsum a or nearly short and not closing apical-inner corners of little shining; head dark brown or black; pronotum and anepisternum 3. Cercyon subopacipennis Nakane has elytra yellowish brown; pronotum a little darker than elytra; the following morphological features on metaventrite. terminal 4 antennomeres dark brown; other antennomeres 1) anterolateral ridges are long and approximating to the light brown; legs brownish; meso- and metaventrites and posterior margin of metaventrite (Fig. 4), 2) femoral lines abdominal ventrites brown or dark brown; preepisternal plate are distinct and elongated, and reaching anterior corners of of mesothorax and pentagonal median portion of metaventrite Ⓒ Japanese Society of Systematic Entomology 132 Hoshina, H. Figs. 1–7. Peltocercyon subopacipennis (Nakane). 1, body; 2, intervals between elytral series; 3, preepisternal plate of mesothorax; 4, metaventrite; 5, male sternite 9; 6, aedeagus, ventral view; 7, ditto, lateral view. Scale A: 1.0 mm for Fig. 1. Scale B: 0.2 mm for Fig. 3. Scale C: 0.5 mm for Fig. 4. Scale D: 0.2 mm for Fig. 5. Scale E: 0.5 mm for Figs. 6 and 7. May 30, 2016, JJSE 22 (1) Taxonomic Report of Peltocercyon 133 metaventrite (Fig. 4), 3) anterolateral ridges and femoral (Coleoptera). vol. 2. 416 pp., Apollo Books, Stenstrup. lines cross each other, thus triangular-like areas are formed Hansen, M., 2004. Family Hydrophilidae. p. 44-68. Löbl, I. & near both apical corners of metaventrite (Fig. 4). Those A. Smetana (eds.). Catalogue of Palaearctic Coleoptera. Hydrophiloidea, Histeroidea, Staphylininoidea, vol. 2. 942 pp. morphological features are shown in the genus Peltocercyon Apollo Books, Stenstrup. d’Orchymont, 1925 (Hansen, 1991). Therefore, I transfer C. Komarek, A., 2004. Taxonomic revision of Anacaena Thomson, subopacipennis to Peltocercyon in this paper. 1859 I. Afrotropical species (Coleoptera: Hydrophilidae). Koleopterologische Rundschau, 74: 303–349. References Nakane, T., 1965. New or little known Coleoptera from Japan and its adjacent regions. XXIII. Fragmenta coleopterologica, (13): d’Orchymont, A., 1925. Contribution à l’étude des Hydrophilides, 51–54. III. Bulletin et Annales de la Société entomologique de Ryndevich, S. K., 2006. Review of species of genus Cercyon Belgique, 65: 261–295. Leach, 1817 of Russia and adjacent regions. III. Subgenera Fikáček, M., F. Hebauer, & M. Hansen, 2009. Taxonomic revision Clinocercyon Orchymont, 1942 and Conocercyon Hebauer, of New World species of the genus Oosternum Sharp 2003 (Coleoptera: Hydrophilidae). Zoosystematica Rossica, (Coleoptera: Hydrophilidae: Sphaeridiinae) I. Definition of 15: 313–320. species groups and revision of the Oosternum aequinoctiale Short, A. E. Z. & M. Fikáček, 2011. World catalogue of the group. Zootaxa, (2054): 1–37. Hydrophiloidea (Coleoptera): additions and corrections II Hansen, M., 1991. The hydrophiloid beetles. Phylogeny, (2006–2011). Acta Entomologica Musei Nationalis Pragae, classification and a revision of the genera (Coleoptera, 51: 83–122. Hydrophilidae). Biologiske Skrifter, Det Kongelige Danske Videnskabernes Selskab, 40: 1–367. [Received: April 29, 2016; accepted: May 15, 2016] Hansen, M., 1999. World of catalogue of insects. Hydrophiloidea May 30, 2016, JJSE 22 (1).