Orphnebius incrassatus, Assing, 2015

Assing, Volker, 2015, On the Orphnebius fauna of the East Palaearctic region. VI. Six new species from China and Taiwan, and additional records (Coleoptera: Staphylinidae: Aleocharinae: Lomechusini), Linzer biologische Beiträge 47 (1), pp. 101-125 : 114-115

Orphnebius incrassatus nov.sp.

( Figs 22-25 )

Type material: Holotype ♀: " CHINA: Yunnan, Baoshan Pref., Gaoligong Shan , 33 km SE Tengchong , 2150 m, 24°51'22''N, 98°45'36''E, devast. primery [sic] deciduous forest, litter, wood, mushrooms sifted, 26.VIII.2009, leg. M. Schülke [CH09-08] / Holotypus ♀ Orphnebius incrassatus sp. n., det. V. Assing 2015" ( cAss).

Etymology: The specific epithet (Latin, adjective) alludes to the conspicuously incrassate antennae.

Description: Body length 4.0 mm; length of forebody 1.6 mm. Coloration: forebody black; abdomen yellowish-red, strongly contrasting with the forebody; legs dark-brown with paler tarsi; antennae with antennomeres I-III dark-brown and antennomeres IV-XI blackish.

Head ( Fig. 22 ) 1.25 times as broad as long; distinctly angled posteriorly in lateral view, i.e., dorsal surface meeting with posterior surface at a sharp angle; punctation of dorsal surface extremely fine and sparse. Eyes large and bulging, nearly reaching posterior margin in dorsal view. Antenna ( Fig. 23 ) 1.0 mm long, strongly incrassate; antennomeres IV moderately transverse; V-X strongly transverse, approximately twice as broad as long, of gradually increasing width; XI distinctly elongated, approximately as long as VIII-X combined.

Pronotum ( Fig. 22 ) strongly transverse, nearly 1.5 times as broad as long and 1.45 times as broad as head, broadest approximately in the middle; lateral margins strongly convex in dorsal view; posterior angles obsolete, broadly convex; disc nearly impunctate, only with scattered minute setiferous punctures; microsculpture absent; lateral margins each with few moderately long brownish setae.

Elytra ( Fig. 22 ) slightly shorter, and at posterior margin much broader than pronotum; punctation fine and sparse; pubescence whitish, sparse, and suberect. Hind wings present.

Abdomen ( Fig. 24 ) broad and wedge-shaped, widest at base; tergites III-VI with sharp and pronounced paratergites gradually decreasing in height; tergites III-VI impunctate except for some minute punctures at posterior margins; tergite VII with rather coarse, oblong, and moderately dense non-setiferous punctures in posterior two-thirds; posterior margin of tergite VII with pronounced palisade fringe.

♂: unknown.

♀: tergite VIII posteriorly approximately 20 fine dark setae posteriorly, posterior margin broadly and strongly convex; sternite VIII with broadly and strongly convex posterior margin; sclerites of segments IX and X modified, with dense and moderately long pubescence; spermatheca ( Fig. 25 ) of distinctive shape.

Comment: This species is described exclusively based on a female because the external characters and the shape of the spermatheca are most likely highly distinctive.

Comparative notes: Based on the modified abdominal segments IX-X, O. incrassatus belongs to the O. hauseri group sensu lato. It is distinguished from the species of the O. hauseri group sensu strictu by the strongly transverse pronotum and the shape of the spermatheca. As can be inferred from external characters (head posteriorly angled in lateral view; pronotum strongly transverse and with obsolete posterior angles; chaetotaxy of the abdomen) and the shape of the spermatheca, O. incrassatus is most closely allied to the geographically close O. truncus ASSING, 2009 , from which it differs particularly by the conspicuously incrassate antennae, the darker coloration of the legs and the antennae, and by the shape of the spermatheca. For illustrations of O. truncus see ASSING (2009).

Distribution and natural history: The type locality is situated in the Gaoligong Shan in western Yunnan. The holotype was sifted from leaf litter in a degraded primary forest at an altitude of 2150 m.

Figures

Figs 22-27: Orphnebius incrassatus nov.sp. (22-25) and O. formosanus nov.sp. (26-27): forebody (22); antenna (23); abdomen (24); spermatheca (25, 27); tergite VII (26). Scale bars: 22-24: 0.5 mm; 25-27: 0.2 mm.