Georissus (Neogeorissus) japonicus Sato 1972
Creators: name: Yasuda, Kohei
name: Yoshitomi, Hiroyuki
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Georissidae
Georissus
Georissus japonicus

description: Georissus (Neogeorissus) japonicus Satô, 1972
[Japanese name: Yamato-marudoromushi]
Figs 2D, 3D–F, J–L, 4C, F, I, L, O, 5D, 6D, 7D, 8D, 9D, 10C, 11A, 11E; Table 2
Georissus (Neogeorissus) japonicus Satô, 1972: 210.
Georissus (Neogeorissus) sakaii Satô, 1972: 210. Syn. nov.
Georissus (Neogeorissus) katsuoi Nakane, 1995: 42. Syn. nov.
Georissus (Neogeorissus) japonicus – Satô 1981: 3; 1985: 206. — Hansen 1999: 47.
Georissus (Neogeorissus) sakaii – Satô 1981: 3; 1985: 206. — Hansen 1999: 49.
Georissus (Neogeorissus) katsuoi – Hansen 1999: 47.
Diagnosis
This species is distinguished from other Japanese Neogeorissus species by the combination of following characteristics; distinct granulation of pronotum and elytra; median lobe shorter than paramere (in contrast to median lobe longer than paramere in other Japanese species of Neogeorissus).
Material examined
Holotype of G. (Ne.) japonicus Satô, 1972
JAPAN – Honshu: Niigata Pref. • ♂; Murakami; 8 Aug. 1961; M. Satô leg.; EUMJ (Fig. 3 D, J).
Holotype of G. (Ne.) sakaii Satô, 1972
JAPAN – Shikoku: Tokushima Pref. • ♂; Tsuda Beach; 11 Sep. 1966; M. Sakai leg.; EUMJ (Fig. 3 E, G).
Holotype of G. (Ne.) katsuoi Nakane, 1995
JAPAN – Honshu: Miyagi Pref. • sex unknown; Water-machi, Torinoumi; 26 Aug. 1993; K, Saito leg.; SEHU (Fig. 3 F, I).
Other material
JAPAN – Honshu: Niigata Pref. • 4 ex.; Murakami; 8 Aug. 1961; M. Satô leg.; EUMJ. – Honshu: Shizuoka Pref. • 1 ex.; Hamamatsu, Ishiyama; 25 May 2001; K. Hirai leg.; EUMJ • 1 ex.; Hamamatsu, Enshuhama; 4 Oct. 2001; K. Hirai leg.; EUMJ • 3 ex.; Hamamatsu, Enshuhama; 13 Oct. 2001; K. Hirai leg.; EUMJ • 6 ex.; Hamamatsu-shi, Matsushima-cho, Enshuhama; 13 Oct. 2002; K. Hirai leg.; EUMJ. – Kyushu: Fukuoka Pref. • 8 ex.; Kouge-machi, Shimotoubaru; 23 Jul. 2013; M. Mori leg.; EUMJ.
Redescription
COLORATION (Fig. 2D). Black to dark brown, matt. Body surface often covered with grayish substance.
HEAD (Fig. 6D). Clypeus uneven, provided with large granules sparsely; slr consisted of granules, reaching to posterior third of frons, posteriorly connected to smb by an arc of sparsely arranged granules and formed a pair of half-rounded foveae; smb consisted of tubercles and granules, anterior portion projecting to laterally; lsa with a shallow groove along the posterior margin.
PRONOTUM (Fig. 7D). Relatively large, widest at the middle. Anterior portion provided with granules densely; smlg relatively wide, granulation dense, with longitudinal row of sparse pits. Posterior portion somewhat convex than anterior portion; cd rhomboid, surrounded by granules; s dp oblong oval, larger than cd, surrounded by granules; slb developed, with distinct granules; pg short and narrow, not reaching median portion of sdp; sdn developed, having a few teeth.
ELYTRA. Humeral bulges distinct. All intervals slightly elevated, provided with distinct lows of granules. Elytral punctures distinct. Lateral ridges on each elytron highly elevate, bearing distinct granules. Hind wings fully developed.
ABDOMEN (Fig. 8D). Lateral margin of ventrites uniformly narrowing posterior. Granules of ventrite 1 large and dense. Granulation of ventrites 2–4 indistinct, ventrite 5 distinct and sparse.
MALE GENITALIA (Fig. 9D). Aedeagus 0.30 mm long. Parameres shorter than phallobase, their basal portions combined as wide as anterior portion of phallobase; lateral margins bulbous at median portion; internal margins straight. Median lobe shorter than parameres, subparallel-sided, slightly angular at apex; basal struts short. Phallobase about 2.5 times as long as wide, sides paralleled: posterior portion with large basal foramen.
FEMALE GENITALIA. Latero-tergites 8 forming acute angle (Fig. 10C); apex strongly incurved. Setae of gonostylus short. Spermatheca (Fig. 11E) curved oval, narrowing at apical portion. Bursal sclerite (Fig. 11A) large and asymmetrical, feebly sclerotized.
Remarks
Satô (1972) mentioned that Georissus (Neogeorissus) sakaii was closely related to G. japonicus and distinguished by granules and foveae on body surface. Subsequently, Nakane (1995) described Georissus (Neogeorissus) katsuoi as a new species without comparison with the related species G. sakaii and G. japonicus. Both species were described based on only holotypes, and there have been no additional records until now. After a detailed comparison of holotype and additional specimens of the above three species, we conclude that they are the same species.
Biological notes
This species was collected from coastal sandy beaches (Shizuoka, Tokushima), a river bank (Iwata & Iwata 2012, in Saitama by pit fall trap), or the shores of ponds (Niigata, Fukuoka).
Distribution
Russian Federation (Lafer 1989); Japan: Honshu (Miyagi, Ibaraki, Niigata, Shizuoka Prefs), Shikoku (Tokushima Pref.), Kyushu (Fukuoka Pref.) (Fig. 13).
description: Published as part of Yasuda, Kohei & Yoshitomi, Hiroyuki, 2022, Revision of the genus Georissus (Coleoptera, Hydrophiloidea, Georissidae) of Japan, pp. 111-142 in European Journal of Taxonomy 817 (1) on pages 124-126, DOI: 10.5852/ejt.2022.817.1767, http://zenodo.org/record/6517928