Orphnebius dishamatus, 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 : 110-111

Orphnebius dishamatus nov.sp.

( Figs 9-15 )

Type material: Holotype ♂: " CHINA [12a] - Yunnan, mt. WNW Wuding, mix. forest, 25°38'45''N, 102°06'55''E, 2390 m, 1.IX.2014, V. Assing / Holotypus ♂ Orphnebius dishamatus sp. n., det. V. Assing 2015" ( cAss).

Etymology: The specific epithet (adjective) is composed of the Latin prefix dis- (un-) and an adjective derived from the Latin noun hamus (hook). It alludes to the straight apex of the ventral process of the aedeagus (lateral view).

Description: Body length 4.5 mm; length of forebody 1.7 mm. Coloration: forebody black; abdomen yellowish-red, strongly contrasting with the forebody; legs with dark-brown femora, reddish-brown tibiae, and dark-yellowish tarsi; antennae with antennomeres I-IV pale-reddish, V reddish-brown, and VI-XI blackish.

Head ( Fig. 9 ) approximately 1.3 times as broad as long; punctation fine and sparse. Eyes large and bulging, distinctly longer than distance from posterior margin of eye to posterior constriction in dorsal view. Antenna ( Fig. 10 ) 1.0 mm long, nearly symmetric; antennomeres IV moderately transverse and V-X distinctly transverse, of gradually increasing width; X approximately twice as broad as long; XI distinctly elongated, approximately as long as VIII-X combined.

Pronotum ( Fig. 9 ) transverse, 1.35 times as broad as long and 1.25 times as broad as head, broadest slightly behind middle, more strongly narrowed anteriorly than posteriorly; lateral margins weakly convex in dorsal view; posterior angles moderately marked; disc with very sparse, minute punctures with long greyish setae; microsculpture absent; lateral margins each with three long black setae of nearly half the length of lateral margin, one in anterior angle, one in anterior half, and one in posterior half.

Elytra ( Fig. 9 ) slightly shorter, and at posterior margin much broader than pronotum; punctation fine and sparse; pubescence long, sparse, and suberect. Hind wings present.

Abdomen ( Fig. 11 ) 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 and moderately dense non-setiferous punctures and with irregular striate sculpture in posterior three-fourths; posterior margin of tergite VII with pronounced palisade fringe.

♂: tergite VIII posteriorly with two transverse rows of black setae, a submarginal row composed of eight long setae and a marginal row composed of ten shorter setae; sclerites of segments IX and X modified, with dense and moderately long pubescence; median lobe of aedeagus ( Figs 12-13 ) 0.7 mm long; ventral process short, apically straight and acute (not hooked) in lateral view, and of triangular shape in ventral view; crista apicalis rather pronounced; paramere ( Fig. 14 ) 0.6 mm long; paramerite slightly longer than condylite and with four setae at base of velum ( Fig. 15 ).

♀: unknown.

Comparative notes: Based on external characters and particularly on the synapomorphic modifications of segments IX-X and of the aedeagus (shape and internal structures of the median lobe; structure of the parameres), O. dishamatus undoubtedly belongs to the O. hauseri group. Among the species of this group, it is most similar to O. scissus (Yunnan) , from which it differs particularly by the morphology of the antennae ( O. scissus : distinctly asymmetric and longer, approximately 1.2 mm long), the less dense non-setiferous punctures on the abdominal tergite VII, and by the morphology of the median lobe of the aedeagus ( O. scissus : 0.75 mm long; apex of ventral process weakly hooked in lateral view; crista apicalis smaller and much more oblique) and of the parameres ( O. scissus : condylite much shorter, and much shorter than paramerite; paramerite of different shape). For illustrations of O. scissus see ASSING (2009).

Distribution and natural history: The type locality is situated near Wuding in East Yunnan. The holotype was sifted from leaf litter in a mixed forest margin with alder and pine at an altitude of 2390 m.

Figures

Figs 9-15: Orphnebius dishamatus nov.sp.: forebody (9); antenna (10); abdomen (11); median lobe of aedeagus in lateral view (12); median lobe of aedeagus in ventral view (13); paramere (14); apical portion of paramerite (15). Scale bars: 9-11: 0.5 mm; 12-14: 0.2 mm; 15: 0.1 mm.