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 Georissus ( Neogeorissus ) takahashii sp. nov. urn:lsid:zoobank.org:act: 373E0934-2F9D-49BA-96E5-BEBE3023B988 [Japanese name: Takahashi-marudoromushi] Figs 2F , 5G–H , 6G–H , 7G–H , 8G–H , 9F–G , 10E , 11C, G ; Table 2 Diagnosis This species is easily distinguished from other Japanese species of Georissus by the elevated intervals 2, 4, 6. Etymology This species name is dedicated to Dr Keiichi Takahashi, the collector of the type series. Material examined Holotype JAPAN – Okinawa : Iriomote-jima • ♂ ; Nishifunatsuki-gawa ; 23 Oct. 1995 ; K. Takahashi leg.; EUMJ . Paratypes JAPAN – Shikoku : Kochi Pref. • 2 ex. ; Shimanto-shi , Shimoda-Tadenogawa ; 27 Jul. 2009 ; T. and T. Miyata leg.; EUMJ • 24 ex. ; Shimanto-shi , Shimanto-gawa ; 23 Jul. 2011 ; T. and T. Miyata leg.; EUMJ . – Okinawa : Okinawa-jima • 1ex. , Isagawa , Nago-shi ; 1 Sep. 2021 ; M. Nagatsuka leg.; light trap ; HOWP • 1 ex. ; Nago-dake , Nago-shi ; 22 Jun. 2006 ; T. Kato leg.; EUMJ . – Okinawa : Ishigaki-jima • 1 ex. ; Takeda-rindo ; 24°24′11.557″ N , 124°10′01.638″ E ; 150 m alt., 25 Jun. 2010 ; T. Shimada leg.; EUMJ • 11 ex. ; Takeda-rindo ; 24°24′13.597″ N , 124°10′49.973″ E ; 140 m alt.; 25 Jun. 2010 ; T. Shimada leg.; EUMJ • 1 ex. ; Omoto-rindo ; 23 Mar. 1995 ; M. Kimura leg.; EUMJ • 3 ex. ; Omoto-rindo ; 26 Mar. 1996 ; K. Takahashi leg.; EUMJ • 2 ex. ; 23 Oct. 1995 ; K. Takahashi leg.; EUMJ . – Okinawa : Iriomotejima • 4 ex. ; Nishifunatsuki-gawa ; 24 Mar. 1995 ; M. Kimura leg.; EUMJ • 2 ex. ; Takeda ; 26 Oct. 1998 ; K. Takahashi leg.; EUMJ • 3 ex. ; Taisho-ike ; 25 Aug. 1994 ; M. Satô leg.; EUMJ • 2 ex. ; Taisho-ike ; 26 Aug. 1994 ; M. Satô leg.; EUMJ • 1 ex. ; Airagawa-rindo ; 2 Mar. 1998 ; I. Matoba leg.; EUMJ • 1 ex. ; Ohtomi ; 20 Nov. 2003 ; Y. Hirano leg.; EUMJ . Description COLORATION ( Fig. 2F ). Light reddish brown, matt. Body surface often covered with greyish to white substance. HEAD ( Fig. 6G–H ). Clypeus uneven, bearing a few large granules sparsely on median portion; slr consisted of granules, anterior granules distinct, but posterior ones indistinct; reaching to posterior third of frons, posteriorly connected to smb by an arc of sparsely arranged granules and formed a pair of rounded foveae; smb consisted of tubercles and granules; lsa with small indistinct granules sparsely. PRONOTUM ( Fig. 7G–H ). Relatively small, widest in the anterior third. Anterior portion provided with granules and pits sparsely; anterior margin slightly crenellated; smlg relatively narrow, provided with longitudinal row of small pits. Posterior portion strongly convex than anterior portion; cd rhomboid and large, with granules on only lateral portion; sdp oblong oval, larger than cd , with a few granules; slb poorly developed, with indistinct granules; pg wide and triangular, not reaching median portion of sdp ; sdn well developed, having a few teeth. Fig. 8. Ventrites of Georissus spp. A . G . ( G .) canalifer Sharp, 1888 . B . G . ( G .) babai Satô, 1970 . C . G . ( Ni .) granulosus Satô, 1972 . D . G . ( Ne .) japonicus Satô, 1972 . E–F . G . ( Ne .) kurosawai Nakane, 1963 from Hokkaido (E) and Nagano (F). G–H . G . ( Ne .) takahashii sp. nov. from Kochi (G) and Okinawa (F). I . G . ( Ne .) satoi sp. nov. Abbreviation: vt = ventral teeth. Scale bars = 100 μm. ELYTRA. Humeral bulges distinct, bearing granules. Intervals 2, 4, 6 highly elevated, with distinct granules. Elytral punctures regular square, seriate and distinct. Lateral ridges on each elytron highly elevate, bearing distinct granules. Hind wings fully developed. ABDOMEN ( Fig. 8G–H ). Lateral margin of ventrites uniformly narrowing posterior. Ventrite 1 with small and sparse granules. Granulation of ventrites 2‒5 indistinct. MALE GENITALIA ( Fig. 9F–G ). Aedeagus 0.32 mm long. Parameres shorter than phallobase, their basal portions combined as wide as anterior portion of phallobase; lateral margins bulbous at basal portion. Median lobe longer than parameres, widening basally, obtuse at apex; basal struts long. Phallobase about 2.2 times as long as wide, subparallel-sided; posterior portion with large basal foramen. FEMALE GENITALIA. Latero-tergites 8 ( Fig. 10E ) forming obtuse angle; apex strongly incurved. Setae of gonostylus short. Spermatheca ( Fig. 11G ) curved oval, relatively narrowing at apical portion. Bursal sclerite ( Fig. 11C ) large and almost symmetrical, slightly sclerotized. Biological notes This species was collected under rocks near a river (Y. Hisasue pers. com.). Specimens from Kochi Prefecture were collected using a car net trap. Distribution Japan : Shikoku ( Kochi Pref.), Okinawa (Okinawa-jima, Ishigaki-jima, Iriomote-jima) ( Fig. 13 ).