Amaurodera dentata, 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 : 86

Amaurodera dentata spec. nov.

( Figs 130, 135 , 396–399 )

Type material: Holotype ♂: “ Thailand: Phetchaburi, Kaeng Krachan Nat. Pk , 450 m, 19.XI.1985, Burckhardt-Löbl / Holotypus ♂ Amaurodera dentata sp. n., det. V. Assing 2015” ( MHNG).

Paratypes: 2 ♂♂, 3 ♀♀, 7 sex?: same data as holotype ( MHNG, cAss) .

Etymology: The specific epithet (Latin, adjective: with tooth/teeth) alludes to the distinct median tooth on the ventral face of the ventral process of the aedeagus.

Description: Body length 4.0– 4.5 mm; length of forebody 2.0– 2.2 mm. Coloration: forebody reddish to reddish-brown; abdomen: tergites III–IV reddish-yellow, tergites V–VIII dark-brown to blackish-brown with the anterior margin of tergite V and the posterior margins of tergites VII and VIII reddish-yellow or reddish; legs yellowish, with the profemora dark-yellowish to brown and the apical halves of the meso- and metafemora brown; antennae yellowish; maxillary palpi yellowish to brown, with palpomere IV pale-yellowish.

Head ( Fig. 130 ) weakly transverse, broadest across eyes, with sexual dimorphism; punctation sparse and extremely fine; interstices without microreticulation. Eyes large and bulging, but shorter than distance from posterior margin of eye to posterior constriction of head. Antenna ( Fig. 135 ) 2.1–2.3 mm long and very slender.

Pronotum 0.72–0.77 mm long, 1.35–1.40 times as long as broad, and as broad as, or slightly narrower than head; with two erect lateral setae on either side anteriorly; dorsal and lateral surface not meeting at an angle posteriorly; microreticulation reaching lateral carinae only in posterior half; narrow median furrow long, but reaching neither anterior nor posterior margins.

Elytra ( Fig. 130 ) 0.56–0.60 times as long as pronotum; punctation moderately fine and moderately dense; interstices with nearly obsolete microreticulation visible only at high magnification (at least 100 x); pubescence short and depressed. Hind wings present. Metatarsomere I approximately as long as the combined length of II and III, or slightly longer.

Abdomen narrower than elytra; punctation fine and sparse on anterior, even sparser on posterior tergites; interstices with microsculpture composed of transverse meshes; posterior margin of tergite VII with palisade fringe; posterior margin of tergite VIII distinctly serrate.

♂: head with shallow, but extensive median impression; median lobe of aedeagus ( Figs 396–397 ) approximately 0.75 mm long; ventral process distinctly angular in the middle (lateral view); crista apicalis conspicuously long.

♀: head without dorsal impression; spermathecal capsule ( Figs 398–399 ) with strongly dilated distal portion and short proximal portion.

Comparative notes: Regarding its primary sexual characters, A. dentata is similar to A. angularis ASSING, 2015 from North India (Darjeeling), from which it is distinguished by the coloration of the legs and abdominal tergite V ( A. angularis : legs uniformly yellowish; tergite V reddish-yellow, not darker than tergites III and IV), by the larger aedeagus ( A. angularis : 0.6 mm) with a relatively longer, apically and basally less strongly sinuate (lateral view), and less strongly dentate ventral process and with a longer crista apicalis, and by the larger distal portion and basally less strongly curved proximal portion of the spermathecal capsule. Based on the available evidence, these differences are interpreted as interspecific variation. However, the possibility they in fact reflect intraspecific variation cannot be ruled out with certainty. Material from the region between the type localities of both species would be required to confirm, or reject, the hypothesis that A. dentata represents a distinct species. For illustrations of A. angularis see ASSING (2015c).

Distribution and natural history: Kaeng Krachan National Park (approximately at 12°58'N, 99°21'E) is situated some 50 km to the southwest of Phetchaburi in central western Thailand, close to the border with Burma. The type specimens were collected at an altitude of 450 m.

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 396–419. Amaurodera dentata (396–399), A. parvoculata (400–404), A. thailandensis (405–410), A. fasciata (411–414), and A. meorum (415–419: 415–416, 419:Khao Yai Nat.Park):median lobe of aedeagus in lateral and in ventral view (396–397, 400–402, 405–409, 411–412, 415–418); spermatheca (398–399, 403–404, 410, 413–414, 419). Scale bars: 0.2 mm.