Lathrobium glabrimpressum, Assing, 2014

Assing, Volker, 2014, New species and records of Lathrobium from the Palaearctic region, primarily from Nepal (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 64 (1), pp. 1-28 : 25-27

Lathrobium glabrimpressum sp. n.

( Figs 140–148 )

Type material: Holotype : “ CHINA: P. R. CHINA, Yunnan, E slope N Gaoligongshan, N 27°46.8' E 098°33.1', 12–15.vi.2009, 2000–3000 m, sifting1–7, V. Grebennikov / Holotypus  Lathrobium glabrimpressum sp. n., det. V. Assing 2013” ( CAS).

Paratypes: 1 : same data as holotype (cSme); 1 : “ CHINA: P. R. CHINA, Yunnan, E slope N Gaoligongshan, N 27°47'22.1" E 098°32'17.7", 24.v.2010, 3027 m, sifting21, V. Grebennikov” (cAss) .

Etymology: The specific epithet is an adjective composed of the Latin adjectives glaber (bald, without hair) and

impressus (impressed). It alludes to the non-pubescent impression of the male sternite VIII.

Description: Relatively small species; body length 5.0– 5.5 mm; length of forebody 2.4–2.7 mm. Habitus as in Fig. 140 . Coloration: forebody reddish-brown to brown; abdomen dark-brown to blackish-brown; legs dark-yellowish; antennae reddish.

Head ( Fig. 141 ) 1.05–1.08 times as long as broad, more or less distinctly dilated behind eyes; punctation sparse and moderately coarse; interstices with microreticulation, distinctly broader than diameter of punctures. Eyes weakly projecting from lateral contours of head and small, approximately one-fourth as long as postocular region in dorsal view and composed of little more than 20 ommatidia. Antenna 1.4–1.5 mm long.

Pronotum ( Fig. 141 ) of rather variable shape, 1.20– 1.28 times as long as broad and as broad as, or slightly broader than, head; punctation similar to that of head, but slightly denser; impunctate midline moderately broad; interstices without microsculpture.

Elytra ( Fig. 141 ) short, 0.56–0.60 times as long as pronotum, very weakly dilated posteriad; humeral angles moderately marked; punctation sparse, shallower than that of head and pronotum; interstices without microsculpture. Hind wings completely reduced. Protarsomeres I–IV with moderate sexual dimorphism.

Abdomen approximately 1.05 times as broad as elytra; punctation fine and dense; interstices with microsculpture; posterior margin of tergite VII without palisade fringe; tergite VIII with weakly pronounced sexual dimorphism.

: protarsomeres I–IV distinctly dilated; tergite VIII with weakly convex posterior margin; sternite VII ( Fig. 142 ) distinctly transverse, posteriorly with shallow median impression of triangular shape, this impression with cluster of long black setae on either side, posterior margin broadly concave; sternite VIII ( Fig. 143 ) oblong, approximately 1.08 times as long as broad and with oblong median impression posteriorly, this impression without setae in the middle and laterally with a cluster of long black setae on either side, posterior excision U-shaped and approximately 0.15 times as deep as length of sternite; aedeagus ( Figs 144–145 ) approximately 0.9 mm long and symmetric; ventral process slender, curved, and apically acute in lateral view; dorsal plate with distinctly sclerotized, moderately long, basally broad, and apically spine-shaped apical portion ( Fig. 146 ), and with short membranous basal portion; internal sac without distinct spines, but with long dark membranous structures.

: protarsomeres I–IV moderately dilated, slightly less so than in male; posterior margin of tergite VIII more strongly convex than in male; sternite VIII ( Fig. 147 ) distinctly oblong and strongly convex posteriorly; tergite IX ( Fig. 148 ) with rather long and undivided antero-median portion and with slender postero-lateral processes; tergite X ( Fig. 148 ) long, slender, moderately convex in cross-section anteriorly, and noticeably longer than antero-median portion of tergite IX.

Comparative notes: Lathrobium glabrimpressum is distinguished from all other species recorded from the Gaoligong Shan by the distinctive morphology of the aedeagus, as well as by the shapes and chaetotaxy of the male sternites VII and VIII, from most species also by the undivided antero-median portion of the female tergite IX. For illustrations of other species known from the Gaoligong Shan see ASSING (2013b) and WATANABE & XIAO (1997, 2000). Closer phylogenetic affiliations to any of the species and species groups previously recorded from Yunnan ( ASSING 2013b) are not evident.

Distribution and natural history: The type material was sifted in two geographically close localities in the northern Gaoligong Shan. One of the paratypes was collected at an elevation of approximately 3030 m, the other two specimens at an altitude between 2000 and 3000 m.

Figures

Figs 140–154: Lathrobium glabrimpressum sp. n. (140–148) and L. smetanai sp. n. (149–154): habitus (140, 149); forebody (141, 150); male sternite VII (142, 151); male sternite VIII (143, 152); aedeagus in lateral and in ventral view (144–145, 153); apex of dorsal plate of aedeagus in dorsal view (146); female sternite VIII (147); female tergites IX–X (148); apical portion of aedeagus in ventral view (154). Scale bars: 140–141, 149–150: 1.0 mm; 142–145, 147–148, 151–154: 0.5 mm; 146: 0.1 mm.