Lathrobium verminatum, Assing, 2013

Assing, V., 2013, On the Lathrobium fauna of China IV. Six new species from Sichuan (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 45 (1), pp. 155-170 : 164-166

Lathrobium verminatum nov.sp.

( Figs 28-35 )

Type material: Holotype ♂: " China Sichuan, Xiling Mt. 1600-2400, litter 30.07.- 4.08.96 leg. S. Kurbatov / Holotypus ♂ Lathrobium bisuditum sp.n. det. V. Assing 2013" ( MHNG). Paratype ♂: same data as holotype ( cAss) . Paratypes: 1♂, 1♀: same data as holotype ( MHNG, cAss).

Etymology: The specific epithet (Latin, adjective: with worms, worm-shaped) refers to the shape of the internal structure of the aedeagus.

Description: Small species; body length 6.8-7.8 mm; length of forebody 2.9- 3.2 mm. Habitus as in Fig. 28 . Coloration: body dark-brown with dark-reddish to reddish-brown elytra; legs and antennae reddish.

Head ( Fig. 29 ) approximately as long as broad; punctation moderately coarse and moderately dense; interstices with fine, but distinct microreticulation. Eyes moderately small, approximately one third as long as postocular region in dorsal view, composed of approximately 40 defined ommatidia. Antenna approximately 1.7 mm long.

Pronotum ( Fig. 29 ) slender, 1.30-1.35 times as long as broad and indistinctly broader than head; punctation similar to that of head; impunctate midline relatively narrow; interstices without microreticulation.

Elytra ( Fig. 29 ) short, approximately 0.5 times as long as pronotum; punctation fine, shallow, and moderately dense. Hind wings completely reduced. Protarsomeres I-IV with pronounced sexual dimorphism.

Abdomen 1.10-1.15 times as broad as elytra; punctation fine and very dense on tergites III-VI, somewhat sparser on tergites VII and VIII; posterior margin of tergite VII without palisade fringe; tergite VIII with weakly pronounced sexual dimorphism.

♂: tergite VIII with weakly convex posterior margin; sternites III-VI unmodified; sternite VII ( Fig. 30 ) moderately transverse, with moderately extensive postero-median impression, this impression with numerous strongly modified stout black setae, posterior margin distinctly concave in the middle; sternite VIII ( Fig. 31 ) distinctly transverse, with postero-median impression, posterior portion of impression with distinctly modified short and stout black setae, posterior excision relatively large, nearly V-shaped; aedeagus ( Figs 32-33 ) rather large in relation to body size, 1.2 mm long and symmetric; ventral process of distinctive shape, relatively long, slender, and apically acute; dorsal plate with short and broad, flat, distinctly sclerotized, and apically weakly convex (dorsal view) apical portion, basal portion completely reduced, not noticeable; internal sac with curved internal structure of distinctive shape.

♀: posterior margin of tergite VIII obtusely angled in the middle; sternite VIII ( Fig. 34 ) 0.9 mm long, weakly oblong, posterior margin convexly produced; tergite IX ( Fig. 35 ) with rather long and undivided antero-median portion, and with moderately long and slender postero-lateral processes; tergite X ( Fig. 34 ) nearly flat, somewhat longer than antero-median portion of tergite X.

Comparative notes: The male sexual characters, particularly the derived morphology of the aedeagus (shapes of dorsal plate and of internal structure) do not suggest closer affiliations to any of the other described Lathrobium species from Sichuan. From the sympatric L. bisuditum , L. verminatum is readily distinguished by smaller body size, the greater number of ommatidia of the eyes, and by the completely different sexual characters.

Distribution and natural history Like L. bisuditum , L. verminatum is probably endemic to the Xiling Xue Shan, where the specimens were sifted from litter.

Figures

Figs 28-35: Lathrobium verminatum nov.sp.: (28) habitus; (29) forebody; (30) male sternite VII; (31) male sternite VIII; (32-33) aedeagus in lateral and in ventral view; (34) female sternite VIII; (35) female tergites IX and X. Scale bars: 28-29: 1.0 mm; 30-35: 0.5 mm.