Georissus (Neogeorissus), Sato, 1972

Yasuda, Kohei & Yoshitomi, Hiroyuki, 2022, Revision of the genus Georissus (Coleoptera, Hydrophiloidea, Georissidae) of Japan, European Journal of Taxonomy 817 (1), pp. 111-142 : 123-124

Subgenus Neogeorissus Satô, 1972

Neogeorissus Satô, 1972: 209 . Type species: Georissus japonicus Satô, 1972 (by original designation).

Redescription

HEAD. Clypeus uneven, with a line of low granules along the anterior margin. Surface of clypeus provided with scattered granules; slr long, reaching to mid-length of frons. Frons provided with granules and some foveae on median portion; lsa distinct, connecting each other, forming U-shape. Mandibles ( Fig. 4L ) relatively large; median lateral margin curving strongly, apex unidentate or bidentate, mola well developed. Antennae ( Fig. 4O ) relatively long; antennomere 4 thin, more than twice as long as antennomere 3; pubescence of club long. Labrum ( Fig. 4F ) not protruding anterior, spines on anterior margin distinct. Apical segment of labial palpi ( Fig. 4I ) oblong oval, with long spines densely. Galea ( Fig. 4C ) densely bearing long setae.

PRONOTUM. Half circular, anterior portion slightly projecting to lateral. Median longitudinal groove reaching at the middle of pronotum. First half of pronotal disc bearing foveae and grooves irregularly, the second half of disc with foveae, especially distinct on a central one (cd) and two oblique large ones just before the posterior margin (sdp). Pronotal sides have dentation at subbasal portion (sdn). Posterior margin provided with granules, bearing grooves along the posterior margins.

ELYTRA. Provided with rows of granules. Puncture distinct. Elytral interstices raised and formed distinct carinae in some species. Humeral bulges distinct, with granules. Lateral ridges on each elytron developed, with granules.

ABDOMEN. Ventrites bearing with granules sparsely. Ventrites 1 and 2 lacking vt in Japanese species, but in some species having distinct vt (e.g., Delève 1967a; Fikáček et al. 2012).

MALE GENITALIA. Aedeagus elongate, subparallel-sided. Parameres shorter than phallobase. Median lobe relatively long. Basal struts long. Phallobase subparallel-sided.

FEMALE GENITALIA. Ovipositor relatively elongate to lateral portion. Two long setae of gonostylus long to short. Spermatheca oblong oval, curving inside, slightly sclerotized. Bursal sclerite slightly asymmetrical, slightly to highly sclerotized.

Remarks

This subgenus is distinguished by the combination of the following characters: pronotal side with dentation (without dentation in Georissus and Nipponogeorissus ); posterior portion of pronotum provided with cd and sdp (without in Georissus and Nipponogeorissus ).

Figures

Fig. 4. Mouth parts and antennae of Georissus spp. A–C. Left maxillae. D–F. Labrum. G–I. Labial palpi. J–L. Left mandibles. M–O. Left antennae. A, D, G, J, M. G. (G.) canalifer Sharp, 1888. B, E, H, K, N. G. (Ni.) granulosus Satô, 1972. C, F, I, L, O. G. (Ne.) japonicus Satô, 1972. Scale bars = 0.1 mm.