Lathrobium bisuditum, 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 : 163-164

Lathrobium bisuditum nov.sp.

( Figs 22-27 )

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).

Etymology: The specific epithet is composed of the Latin prefix bi- (two) and an adjective derived from the Latin noun sudis (pole). It refers to the presence of a pair of long spines in the internal sac of the aedeagus.

Description: Species of intermediate size; body length 7.8-8.7 mm; length of forebody 3.6-3.9 mm. Habitus as in Fig. 22 . Coloration: body dark-brown; legs and antennae reddish.

Head ( Fig. 23 ) 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 moderately small defined ommatidia. Antenna approximately 2.1 mm long.

Pronotum ( Fig. 23 ) slender, 1.3 times as long as broad and approximately 1.05 times as broad as head; punctation similar to that of head; impunctate midline moderately broad; interstices without microreticulation.

Elytra ( Fig. 23 ) approximately 0.53 times as long as pronotum; punctation fine, shallow, and moderately dense. Hind wings completely reduced.

Abdomen 1.15-1.20 times as broad as elytra; punctation fine and dense; posterior margin of tergite VII without palisade fringe.

♂: protarsomeres I-IV strongly dilated; tergite VIII with weakly convex posterior margin; sternites III-VI unmodified; sternite VII ( Fig. 24 ) distinctly transverse, with rather extensive postero-median impression, this impression with numerous distinctly modified stout black setae, posterior margin concave in the middle; sternite VIII ( Fig. 25 ) weakly transverse, with oblong median impression, middle of this impression narrowly without setae, on either side of middle with numerous modified black setae; posterior excision small and broadly V-shaped; aedeagus ( Figs 26-27 ) 1.7 mm long and symmetric, ventral process long, somewhat bisinuate, basally broad, and apically slender in lateral view; dorsal plate with rather long, flat, distinctly sclerotized, and apically acute apical portion, and with minute, barely noticeable basal portion; internal sac with two long sclerotized spines and an additional dark membranous structure.

♀: unknown.

Comparative notes: Like the preceding species, L. bisuditum belongs to the L. bibaculatum group, as can be inferred particularly from the presence of a pair of long sclerotized spines in the internal sac of the aedeagus. It is distinguished from all the species of this group, as well as from the sympatric L. verminatum by the male sexual characters, from the latter additionally by larger body size.

Distribution and natural history The species is probably endemic to the Xiling Xue Shan [ca. 30°54'N, 103°14'E] ( Map 1 ), where the two type specimens were sifted from litter.

Figures

Map 1: Geographic position of the Xiling Xue Shan (filled circle), the Luoji Shan (open triangle), and the type locality of L. formidabile nov.sp. (star) in China.

Figs 22-27: Lathrobium bisuditum nov.sp.: (22) habitus; (23) forebody; (24) male sternite VII; (25) male sternite VIII; (26-27) aedeagus in lateral and in ventral view. Scale bars: 22-23: 1.0 mm; 24- 27: 0.5 mm.