Lathrobium grebennikovi, Assing, 2015

Assing, Volker, 2015, New species and additional records of Lathrobium and Elytrobium from the Palaearctic region, with special reference to the fauna of East Yunnan (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 65 (1), pp. 41-74 : 59-61

Lathrobium grebennikovi spec. nov.

( Figs 79–87 )

Type material: Holotype : “P. R. CHINA, Shaanxi, N slope Qin Ling Shan, N 34°01'07" E 107°51'50", 17.v.2011, 1700–2200 m, sift02, V. Grebennikov / Holotypus  Lathrobium grebennikovi spec. nov., det. V . Assing 2014” ( CAS). Paratypes: 3 , 7 : same data as holotype ( CAS, cSme, cAss) .

Etymology: The species is dedicated to Vasily Grebennikov (currently Ottawa), who collected the type series, also in appreciation of his merits in discovering numerous other novelties in China.

Description: Species of moderate size and with moderately pronounced sexual size dimorphism; body length 7.5–8.5 mm (), 6.2–7.5 mm (); length of forebody 3.6–3.7 mm (), 3.1–3.4 mm (). Coloration: body brown to dark-brown; legs reddish to reddish-brown; antennae dark-reddish.

Head ( Fig. 79 ) 1.00–1.05 times as long as broad, widest behind eyes; punctation moderately coarse and moderately dense, slightly less dense in median dorsal portion; interstices with shallow, but distinct microreticulation. Eyes flat, not projecting from lateral contours of head, and small, approximately one-fourth as long as postocular region in dorsal view, or slightly longer, and composed of fewer than 50 ommatidia. Antenna 1.8–1.9 mm () or 1.5–1.7 mm () long.

Pronotum ( Fig. 79 ) moderately slender, approximately 1.3 times as long as broad and as broad as head; punctation similar to that of head; impunctate midline rather narrow; interstices without microsculpture.

Elytra ( Fig. 79 ) approximately 0.55 times as long as pronotum, weakly dilated posteriad; humeral angles moderately marked; punctation shallow and moderately dense; interstices without microsculpture. Hind wings completely reduced. Protarsomeres I–IV with pronounced sexual dimorphism.

Abdomen approximately 1.1 times as broad as elytra; punctation fine and moderately dense, gradually becoming less dense towards posterior tergites; interstices with shallow transverse microsculpture; posterior margin of tergite VII without palisade fringe; tergite VIII with very weakly pronounced sexual dimorphism.

: protarsomeres I–IV strongly dilated; tergite VIII with weakly convex, nearly truncate posterior margin; sternite VII ( Fig. 80 ) strongly transverse, approximately 1.65 times as broad as long, with rather extensive and moderately pronounced postero-median impression of triangular shape, this impression with a cluster of rather weakly modified black setae, posterior margin broadly concave; sternite VIII ( Fig. 81 ) transverse, approximately 1.1 times as broad as long, narrowly impressed along middle, middle of this impression without setae, on either side of middle with dense moderately modified setae, posterior margin with small median excision; aedeagus ( Figs 82–85 ) 1.30–1.35 mm long, nearly symmetric; ventral process apically bent and acute in lateral view; dorsal plate distinctly sclerotized, with long and broad apical portion with median carina (dorsal view) and with moderately short basal portion; internal sac with moderately sclerotized structures, but without distinct spines.

: protarsomeres I–IV dilated, but much less so than in male; sternite VIII ( Fig. 86 ) approximately 1.1 mm long and 1.25 times as long as broad, posterior margin strongly and convexly projecting in the middle; tergite IX ( Fig. 87 ) with long and undivided median portion and with moderately slender postero-lateral processes; tergite X ( Fig. 87 ) moderately convex in cross-section, 1.10–1.15 times as long as antero-median portion.

Comparative notes: As can be inferred from the similar modifications of the male and female sexual characters, L. grebennikovi belongs to the L. varisternale group (see ASSING 2013a), which previously included 14 species distributed in the Qinling Shan and adjacent mountain ranges ( ASSING 2013a; PENG et al. 2013). It is distinguished from all the species of this group primarily by the morphology of the aedeagus. The latter is most similar to that of L. inflexum ASSING, 2013 from a mountain range to the southeast of Longnan in southern Gansu. From this species, L. grebennikovi is additionally distinguished by slightly larger body size, the sexual size dimorphism, the more pronounced clusters of modified setae on the male sternites VII and VIII, the absence of a distinct median concavity of the posterior margin of the male sternite VII, the larger aedeagus with a differently shaped ventral process and with a distinctly sclerotized basal portion of the dorsal plate, the differently shaped female sternite VIII, and the longer female tergite X ( L. inflexum : female tergite X shorter than antero-median portion of tergite IX). For illustrations of L. inflexum and other species of the L. varisternale group see ASSING (2013a) and PENG et al. (2013).

Distribution and natural history: The type locality is situated in the northern Qinling Shan in southern Shaanxi. The type specimens were sifted together with L. brevitergale at altitudes between 1700 and 2200 m.

Figures

Figs 79–92: Lathrobium grebennikovi spec. nov.(79–87) and L. cavisulcatum spec. nov. (88–92): forebody (79, 88); male sternite VII (80, 89); male sternite VIII (81, 90); aedeagus in lateral view (82, 91); aedeagus in dry preparation in lateral, ventral, and dorsal view (83–85); female sternite VIII (86); female tergites IX–X (87); aedeagus in ventral view (92). Scale bars: 79, 88: 1.0 mm; 80–87, 89–92: 0.5 mm.