Amaurodera arunica, Assing, 2016

Assing, Volker, 2016, On some Lomechusini of the Palaearctic and Oriental regions (Coleoptera: Staphylinidae: Aleocharinae), Beiträge Zur Entomologie = Contributions to Entomology 66 (1), pp. 13-111 : 82-83

Amaurodera arunica spec. nov.

( Figs 126–127, 132 , 384–388 )

Type material: Holotype ♂: “E-NEPAL, Arun Valley , env. Tashigaon, 2200–2400 m, 12.+ 28.–29.V.2014, 27°37'N, 87°14'E, leg. Schmidt / Holotypus ♂ Amaurodera arunica sp. n., det. V. Assing 2015” ( NME).

Paratypes: 19 exs.: same data as holotype ( NME, cAss) .

Etymology: The specific epithet is an adjective derived from Arun, the name of the valley where the type locality is situated.

Description: Body length 5.8–6.8 mm; length of forebody 2.8–3.1 mm. Coloration: body black, with tergites III–IV and the anterior portions of the anterior paratergites often slightly paler; legs: profemora blackish-brown to blackish, meso- and metafemora blackish-brown to blackish with dark-yellowish bases, tibiae brown, tarsi yellowish-brown; antennae blackish-brown to blackish, with antennomere IX reddish to brown, the basal 1–3 antennomeres brown to dark-brown, and often (the bases of) antennomeres II and III dark-reddish to reddish-brown; maxillary palpi brown with yellowish palpomere IV.

Head ( Fig. 126 ) weakly oblong, broadest across eyes, without sexual dimorphism; punctation sparse and extremely fine; interstices with very shallow, nearly obsolete microreticulation. Eyes 0.5–0.6 times as long as the distance from posterior margin of eye to posterior constriction of head. Antenna ( Fig. 132 ) approximately 3.1–3.4 mm long and very slender.

Pronotum ( Figs 126 , 384 ) 1.15–1.25 mm long, nearly 1.5 times as long as broad, and slightly broader than head; dorsal surface matt; dorsal and lateral surface meeting at an angle posteriorly; microreticulation reaching lateral carinae only in posterior portion; narrow median furrow long, but reaching neither anterior nor posterior margins.

Elytra ( Fig. 126 ) short, approximately 0.45 times as long as pronotum; punctation dense, distinct, and somewhat granulose; pubescence short and depressed. Hind wings reduced. Metatarsomere I approximately as long as the combined length of II–IV.

Abdomen ( Fig. 127 ) approximately 1.15 times as broad as elytra; tergites III–V with fine (but distinct) and moderately sparse punctation; tergite VI with extremely fine and very sparse punctation; tergite VII with sparse and fine punctation only in posterior portion, anterior portion practically impunctate; tergite VIII with somewhat granulose punctation in posterior third, anterior two-thirds impunctate; microsculpture extremely shallow, nearly obsolete, distinct only on tergite VIII; posterior margin of tergite VII with palisade fringe; posterior margin of tergite VIII distinctly serrate.

♂: sternite VIII noticeably longer than tergite VIII, posterior margin distinctly convex; median lobe of aedeagus ( Figs 385–386 ) 0.72–0.77 mm long and of compact shape; ventral process strongly sinuate in lateral view, basally broad in ventral view; paramere approximately 0.75 mm long.

♀: sternite VIII approximately as long as tergite VIII, posterior margin broadly convex; spermatheca as in Figs 387–388 .

Comparative notes: Based on the external and the sexual characters, A. arunica belongs to the A. silvana group (see ASSING 2003). The male and female primary sexual characters are most similar to those of A. silvana PACE, 1992 (Central Nepal: Annapurna and Dhaulagiri ranges), from which the new species differs particularly by the shape of the ventral process of the aedeagus (ventral process much more sinuate in lateral view and less broad in ventral view), by the coloration of the legs ( A. silvana : femora and tibiae practically completely black), the glossy head and elytra ( A. silvana : head and elytra with pronounced microsculpture and matt), as well as by the shorter and more slender elytra. The only other species of the A. silvana group recorded from East Nepal is A. kleebergi ASSING, 2006 (Rolwaling Himal), from which A. arunica differs by a shorter and slightly less oblong pronotum ( A. kleebergi : pronotum 1.3–1.4 mm long), the coloration of the legs and maxillary palpi ( A. kleebergi : tibiae completely black or nearly so; femoral bases not yellow; maxillary palpomeres II and III blackish-brown to black), the much finer and less dense punctation of the elytra, the absence of an oblong impression on the elytra, as well as the longer, more strongly sinuate, and more slender ventral process of the aedeagus.

The remaining species known from East Nepal belong to other species groups. They are of distinctly smaller size and paler coloration, and/or their pronotum is subject to a pronounced sexual dimorphism. Moreover, their genitalia are of completely different shapes. For illustrations of the previously described Himalayan Amaudera species see ASSING (2003, 2005a, 2006a, 2015c).

Distribution and natural history: The type locality is situated in the Arun valley in East Nepal. The reduced hind wings and the restricted distributions of other species of the A. silvana group suggest that A. arunica is endemic to this region.

Figures

Figs 119–143. Drusilla bifida (119–122), Rabdotodrusilla pectinata (123–125), Amaurodera arunica (126–127, 132), A. gilvios (128, 133), A. reticulata (129, 134), A. dentata (130, 135), A. parvoculata (131, 136), A. thailandensis (137–138), A. fasciata (139), A. meorum(140),A. disparicollis (141), A. spinans (142),andA. varicollis(143):forebody (119, 123, 126, 128–131); head and pronotum (120); antenna (121, 124, 132–143); abdomen (122, 125, 127). Scale bars: 1.0 mm.

Figs 379–395. Drusilla bifida (379), Rabdotodrusilla pectinata (380–383), Amaurodera arunica (384–388), A. gilvios (389–390, 395), and A. reticulata (391–394): sutural portion of left elytron (379); median lobe of aedeagus in lateral and in ventral view (380– 381, 385–386, 389–392); male tergite VIII (382); male sternite VIII (383); male pronotum (384); spermatheca (387–388, 395); subapical portion of median lobe of aedeagus in dry preparation (393); subapical portion of median lobe of aedeagus in transparent light (394). Scale bars: 384: 0.5 mm; 379–383, 385–392, 395: 0.2 mm; 393–394: 0.1 mm.