Lathrobium erectum, 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 : 64-65

Lathrobium erectum spec. nov.

( Figs 102–110 )

Type material: Holotype : “ CHINA, Guizhou, Fanjing Shan , 27°54'N, 108°42'E, 1800–2000 m, 5.–11.VI.2014, pitfall, leg. C. Reuter / Holotypus  Lathrobium erectum spec. nov., det. V. Assing 2014” (cAss).

Etymology: The specific epithet (Latin, adjective) alludes to the shape of the conspicuous process (lateral view) at the base of the ventral process of the aedeagus.

Description: Species of rather large size; body length 11.0 mm; length of forebody 5.1 mm. Habitus as in Fig. 102 . Coloration: body dark-brown; legs and antennae dark-reddish.

Head ( Fig. 103 ) approximately as long as broad, weakly dilated behind eyes; punctation not very coarse, rather dense in lateral, anterior, and posterior dorsal portions, sparser in median dorsal portion; interstices with very shallow, barely noticeable microreticulation, on average approximately as broad as diameter of punctures in lateral and posterior dorsal portions. Eyes weakly convex, not projecting from lateral contours of head, and small, approximately one-fifth as long as postocular region in dorsal view and composed of slightly more than 50 ommatidia. Antenna 2.9 mm long.

Pronotum ( Fig. 103 ) moderately slender, 1.29 times as long as broad and 1.02 times as broad as head; punctation similar to that of head; impunctate midline moderately broad; interstices without microsculpture.

Elytra ( Fig. 103 ) short, 0.49 times as long as pronotum, not distinctly dilated posteriad; humeral angles moderately marked; punctation rather dense and defined; interstices without microsculpture. Hind wings completely reduced.

Abdomen approximately 1.05 times as broad as elytra; punctation fine, rather dense on tergites III–VI, sparser on tergite VII; interstices with shallow transverse microsculpture; posterior margin of tergite VII without palisade fringe.

: protarsomeres I–IV strongly dilated; tergite VIII with weakly convex posterior margin; sternite VII ( Fig. 104 ) moderately strongly transverse, approximately 1.4 times as broad as long, with rather pronounced postero-median impression of triangular shape, this impression with a cluster of modified stout black setae, posterior margin broadly concave, in the middle somewhat more distinctly concave; sternite VIII ( Fig. 105 ) as long as broad, with pronounced median impression in posterior half, this impression with conspicuously dense modified stout black setae, posterior excision broadly V-shaped, its depth approximately one-seventh the length of sternite; aedeagus ( Figs 106–109 ) 1.9 mm long, strongly asymmetric, with small basal portion, and of remarkably modified morphology; ventral process strongly asymmetric, of very distinctive shape, partly fused with the asymmetric dorsal plate, and at base with conspicuous erect process; internal sac with a very long, slender, and basally bifid sclerotized spine ( Fig. 110 ) and with a membranous ringshaped structure.

: unknown.

Comparative notes: Based on the morphology of the aedeagus (strongly asymmetric; small basal portion; internal sac with a long sclerotized spine) and on the male secondary sexual characters, L. erectum is attributed to the L. fissispinosum group (see ASSING 2013a). The only other species of this group recorded from Guizhou is L. pium ASSING, 2013 (Leigong Shan), from which L. erectum differs by larger size ( L. pium : length of forebody 4.5–4.7 mm), weakly pronounced microsculpture on the head, smaller eyes, the more oblong pronotum ( L. pium : approximately 1.2 times as long as broad), the completely different modifications of the male sternites VII and VIII, and by the distinctive shape of the aedeagus. For illustrations of L. pium see ASSING (2013b).

Distribution and natural history: The Fanjing Shan is situated in the northeast of Guizhou, not far from the borders with Hunan and Chongqing. The holotype was collected with a pitfall trap at an altitude between 1800 and 2000 m.

3.5. Taiwan

Figures

Figs 102–110: Lathrobium erectum spec. nov.: habitus (102); forebody (103); male sternite VII (104); male sternite VIII (105); aedeagus in lateral and in ventral view (106–107); aedeagus in dry preparation in lateral and in ventral view (108–109); internal structure of aedeagus (110). Scale bars: 102–103: 1.0 mm; 104–110: 0.5 mm.