Revision of the genus Georissus (Coleoptera, Hydrophiloidea, Georissidae) of Japan Author Yasuda, Kohei C660A24E-D4D7-4985-951F-A4093FFBEE57 Entomological Laboratory, Faculty of Agriculture, Ehime University, Tarumi 3 - 5 - 7, Matsuyama, 790 - 8566 Japan. koheizari303@gmail.com Author Yoshitomi, Hiroyuki 744FA6FC-2D84-41B7-8A6C-C1611CC68EE1 Entomological Laboratory, Faculty of Agriculture, Ehime University, Tarumi 3 - 5 - 7, Matsuyama, 790 - 8566 Japan. hymushi@agr.ehime-u.ac.jp text European Journal of Taxonomy 2022 2022-05-03 817 1 111 142 http://dx.doi.org/10.5852/ejt.2022.817.1767 journal article 55730 10.5852/ejt.2022.817.1767 529dc516-47b9-424e-93ac-3787e407e100 2118-9773 6517928 FFB05CE7-3712-4FD0-91B4-FD84863CF9D7 Genus Georissus Latreille, 1809 Georissus Latreille, 1809: 377 . Type species: Pimelia pygmaea Fabricius, 1798 (= Byrrhus crenulatus Rossi, 1794 ) [monotypy]. Cathammistes Illiger, 1807a: 297 ; 1807b: 322 [suppressed, cf. ICZN 1998: 58 ]. Gender: masculine. Georyssus [unjustified emendation] – Stephens 1828: 105 . Supplementary description BODY. Black to reddish brown, oval, strongly convex dorsally. CLYPEUS. Uneven, with granules or carinae on its surface; articulated carinae arising at antero-lateral portion of clypeus and reaching anterior portion of frons ( slr in Fig. 1A ); a pair of distinct bulges ( smb in Fig. 1A ) on antero-median portion of frons (in Nipponogeorissus and Neogeorissus ); sides of frons smooth, lacking granules ( lsa in Fig. 1A ). Eyes developed, not protuberant. Antennae ( Fig. 4M–O ) short, 9-segmented, with 3-segmented pubescent club (7-segmented with one-segmented club in Australian species: Fikáček 2019 ). Mandibles ( Fig. 4J–L ) large and well sclerotized, partly concealed beneath clypeus and labrum; antero-lateral margin forming obtuse angle; apex pointed; internal margin with microtrichia except apex. Maxillary palpi ( Fig. 4A–C ) 4-segmented; palpomere 4 longest and nearly same length as palpomeres 1–3 combined. Labrum ( Fig. 4D–F ) semicircular, widest at base; lateral margins fringed with spines. Mentum subtriangular, strongly narrowed anteriorly, with long setae on disc. Labial palpi ( Fig. 4G–I ) as long as mentum; apical palpomere oval to oblong oval, densely bearing spines in interior margin. PRONOTUM. Half oval to trapezoidal, divided into anterior and posterior portions; anterior portion irregularly arranged with granules or short grooves and pits, with shallow median longitudinal groove ( smlg in Fig. 1B ); posterior portion more convex than anterior portion, with large fovea on anteromedian portion ( cd in Fig. 1B ); posterior sides of cd with a pair of distinct foveae ( sdp in Fig. 1B ) (only in Neogeorissus ); sublateral potion of posterior portion with distinct bulge ( slb in Fig. 1B ); behind of slb with deep groove ( pg in Fig. 1B ); sides somewhat protruding laterally, having dentation ( sdn in Fig. 1B ) in Neogeorissus . LEGS. Protrochantins concealed. Procoxae large, plate-like, concealing prosternum. Femora somewhat flattened. Tibiae slender, especially protibiae rather flattened. Tarsal formula 5-5-5 (5-4- 4 in Australian species: Fikáček 2019 ). ELYTRA. Provided with ten punctate rows. All or alternate intervals slightly to highly raised. Hind wings well developed or absent in some species. VENTRITES. Ventrites 1 and 2 connate; ventrite 1 large, with distinct granules; posterior margin of ventrite 1 and anterior margin of ventrite 2 with a pair of ventral teeth ( vt in Fig. 8A ). Fig. 1. Georissus (Ne.) kurosawai Nakane, 1963 , showing terminology. A . Head. B . Pronotum. Abbreviations: cd = central depression; lsa = lateral smooth area; pg = posterior grooves; sdn = subbasal dentation; sdp = subbasal depression; slb = sublateral bulge; slr = sublateral ridge; smb = submedian bulge; smlg = shallow median longitudinal groove. MALE GENITALIA ( Fig. 9 ). Aedeagus trilobate type , almost symmetrical. FEMALE GENITALIA. Gonocoxite ( Fig. 10 ) long, almost cross each other posteriorly. Gonostylus short, provided with two long setae at apex. Median sclerite unilobed, densely bearing long setae. Spermatheca ( Fig. 11E–H ) slightly sclerotized, elongated oval. Bursal sclerite ( Fig. 11A–D ) somewhat developed in subgenus Neogeorissus , slightly asymmetrical. Key to the species of the genus Georissus from Japan 1. Posterior portion of pronotum with a shallow median longitudinal groove, lacking granules or cd and sdp . Elytra bearing seriate large punctures. Elytral interstices smooth. Aedeagus broad, median lobe short ( Fig. 9A–B ). Subgenus Georissus Latreille, 1809 ............................................................ 2 – Posterior portion of pronotum provided with granules or foveae. Elytra bearing distinct granules. Elytral interstices raised. Aedeagus narrow, median lobe short or long ( Fig. 9C–H ) ...................... 3 2. Granules of clypeus distinct, large and dense ( Fig. 6B ). Posterior portion of pronotum lacking a longitudinal groove ( Fig. 7B ). Internal margins of parameres covered with long setae ( Fig. 9B ) ..... ...................................................................................................................... G . ( G .) babai Satô, 1970 – Granules of clypeus indistinct, small and sparse ( Fig. 6A ). Posterior portion of pronotum having a shallow longitudinal groove ( Fig. 7A ). Internal margins of parameres covered with short setae ( Fig. 9A ) .............................................................................................. G . ( G .) canalifer Sharp, 1888 3. Posterior portion of pronotum densely bearing granules, lacking cd and sdp . Pronotum lacking sdn ( Fig. 7C ). Aedeagus extremely narrow, phallobase posteriorly widening ( Fig. 9C ). Subgenus Nipponogeorissus Satô, 1972 ........................................................... G . ( Ni .) granulosus Satô, 1972 – Posterior portion of pronotum provided with granules, present cd and sdp . Pronotum having sdn ( Fig. 1B ). Aedeagus narrow, phallobase subparallel-sided ( Fig. 9D–H ). Subgenus Neogeorissus Satô, 1972 ......................................................................................................................................... 4 4. Elytral interstices 2, 4, 6 highly raised ( Fig. 5G–H ) ............................... G . ( Ne .) takahashii sp. nov. – All elytral interstices equally raised ( Fig. 5D–F, I ) .......................................................................... 5 5. Coloration of body black. Elytral granules indistinct ( Fig. 5E–F ) ..................................................... ....................................................................................................... G . ( Ne .) kurosawai Nakane, 1963 – Coloration of body dark reddish brown. Elytral granules distinct ( Fig. 5D, I ) ................................ 6 6. Coloration of body black to dark brown. Granulation of pronotum distinct ( Fig. 7D ). Median lobe shorter than parameres ( Fig. 9D ) ........................................................ G . ( Ne .) japonicus Satô, 1972 – Coloration of dark reddish brown. Granulation of pronotum indistinct ( Fig. 7I ). Median lobe longer than parameres ( Fig. 9H ) ................................................................................. G . ( Ne .) satoi sp. nov.