Orphnebius lunatus, 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 : 47-48

Orphnebius lunatus spec. nov.

( Figs 3, 25 , 207–210 )

Type material: Holotype ♂: “ Lao-NE , Hua Phan prov., 20°12'N 104°01'E, Phu Phan Mt. , ~ 1750 m, 17.v.–3.vi. 2008, Vít Kubáň leg. / Holotypus ♂ Orphnebius lunatus sp. n., det. V. Assing 2015” ( NHMB).

Paratype ♂ [left antenna, right antennomeres X–XI, and left hind leg missing]: “ Laos, 1.–16.v.1999, Louangphrabang pr., 20°33–4'N 102°14'E, Ban Song Cha (5 km W), 1200 m, Vít Kubáň leg.” (cAss) .

Etymology: The specific epithet is the past participle of the Latin verb lunare (to bend) and alludes to the distinctly bent apex of the ventral process of the aedeagus (lateral view).

Description: Body length 3.6–3.7 mm; length of forebody 1.5–1.7 mm. Coloration: head black; pronotum and elytra blackish-brown to black; abdomen pale-reddish; legs with brown femora and reddish tibiae and tarsi; antennae with antennomeres I–IV reddish and V–XI dark-brown to blackish; maxillary palpi brown to darkbrown with yellowish terminal palpomere.

Head ( Fig. 25 ) transverse, 1.17–1.25 times as broad as long; posterior angles completely obsolete; posterior margin of disc convex; punctation fine and sparse; median dorsal portion extensively impunctate; interstices without microsculpture. Eyes large, somewhat longer than distance from posterior margin of eye to posterior constriction of head. Antenna ( Fig. 3 ) 1.0 mm long, moderately incrassate, and weakly asymmetric; antennomere IV small and weakly transverse; antennomeres V–X of gradually increasing width and increasingly transverse; X twice as broad as long; XI elongate, approximately as long as the combined length of VIII–X.

Pronotum ( Fig. 25 ) moderately transverse, 1.20– 1.25 times as broad as long and 1.15–1.20 times as broad as head, moderately convex in cross-section; posterior angles weakly marked, nearly obsolete; disc with an indistinct median pair of punctures, otherwise nearly impunctate; margins with additional punctures; lateral margins each with three long and erect black setae.

Elytra ( Fig. 25 ) approximately 0.80–0.85 times as long as pronotum; suture distinctly gaping posteriorly; punctation moderately sparse and fine; pubescence pale, fine, long, and sub-erect or depressed on disc. Hind wings fully developed. Metatarsomere I approximately as long as the combined length of II and III.

Abdomen, including tergite VIII ( Fig. 207 ), as in O. cernens .

♂: hemi-tergites IX and tergite X with extremely dense and long pubescence ( O. hauseri type); median lobe of aedeagus ( Figs 208–209 ) approximately 0.7 mm long; ventral process apically hooked in lateral view; internal sac with large and strongly sclerotized structures and with long flagellum; paramere ( Fig. 210 ) small, approximately 0.4 mm long, condylite approximately as long as paramerite, straight, and apically acute.

♀: unknown.

Comment: The somewhat damaged paratype differs from the holotype by slightly less transverse antennomeres VI–IX and by the different shapes of the apex of the ventral process and the crista apicalis of the aedeagus. In other respects, including the shape of the paramere, the two specimens are identical. The differences in the shape of the median lobe of the aedeagus most likely represent artefacts (apex of ventral process slightly deformed and portion between crista apicalis and ventral process apparently slightly damaged in the aedeagus of the holotype).

Comparative notes: Orphnebius lunatus is distinguished from the similar and syntopic O. cernens by a distinctly less transverse head, distinctly smaller eyes, shorter antennae with a shorter antennomere XI, as well as by the completely different shapes of the ventral process of the aedeagus and of the parameres. Based on the male sexual characters, O. lunatus is closely allied to O. scissus ASSING, 2009 from Yunnan, from which it differs by the morphology of the aedeagus (ventral process much more strongly hooked apically and of different shape in ventral view; crista apicalis less pronounced; paramere with condylite of different shape and paramerite with less pronounced lateral incision). For illustrations of O. scissus see ASSING (2009).

Distribution and natural history: The type material was found in two localities in Hua Phan and Louang Phrabang provinces at altitudes of 1200 and approximately 1750 m. Orphnebius cernens , O. fuscapicalis , O. fusicollis , O. spoliatus , O. nigrapicalis , O. extensus , O. reductus , and an unnamed species were recorded from the same localities.

Figures

Figs 1–26. Antenna (1–21) and forebody (22–26) of Orphnebius spp. of the O. hauseri group: spinans (1, 23), cernens (2, 24), lunatus (3, 25), bakeri (4, 26), breviceps (5), extensus (6), serratus (7), integer (8), bicuspis, Laos (9), bicuspis, NE India (10), fusicollis (11), retunsus (12), fodens (13), opticus (14), dilatatus (15), fuscapicalis (16), grandicollis (17, 22), reductus (18), biformis, male (19), biformis, female (20), effeminatus (21). Scale bars: 22–26: 1.0 mm; 1–21: 0.5 mm.

Figs 197–215. Orphnebius spinans (197–201), O. cernens (202–206), O. lunatus (207–210), and O. grandicollis (211–215): male segments IX–X (197); median lobe of aedeagus in lateral and in ventral view (198–199, 202–203, 208–209, 212); ventral process of aedeagus in ventral view (200, 214); paramere (201, 204, 210, 215); apex of paramere (205); spermatheca (206); tergite VIII (207, 211); ventral process of aedeagus in lateral view (213). Scale bars: 0.2 mm.