Orphnebius reductus, 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 : 58-59

publication ID	https://doi.org/ 10.21248/contrib.entomol.66.1.13-111
DOI	https://doi.org/10.5281/zenodo.5903426
persistent identifier	https://treatment.plazi.org/id/766F7C36-FF9C-FFC5-FF36-7054DA7AFE42
treatment provided by	Felipe
scientific name	Orphnebius reductus
status	sp. nov.

Treatment

Orphnebius reductus View in CoL spec. nov.

( Figs 18 View Figs 1–26 , 49 View Figs 40–53 , 269–273 View Figs 258–276 )

Type material: Holotype ♂: “ 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. / Holotypus ♂ Orphnebiusreductus sp. n., det. V. Assing 2015”( NHMB) . Paratypes: 15 ♂♂, 10 ♀♀ [3 teneral]: same data as holotype ( NHMB, cAss) ; 1 ♀: same data, but 24.iv.–16.v.1999 ( NHMB) ; 1♂: “ Lao, Phongsaly prov. , 21°41–2'N 102°06– 8'E, 28.v.–20.vi.2003, Phongsaly env. , ~ 1500 m, Vít Kubáň leg.” (cAss) .

Etymology: The specific epithet (Latin, adjective) alludes to the conspicuously reduced condylite of the paramere.

Description: Body length 3.8–4.6 mm; length of forebody 1.6–1.9 mm. Coloration: forebody blackish; abdomen pale-reddish; legs yellowish-red, with the profemora yellowish and the meso- and metafemora brown; antennae blackish, with the basal 1–3 antennomeres yellowish; maxillary palpi reddish-yellow with yellowish terminal palpomere.

Head ( Fig. 49 View Figs 40–53 ) strongly transverse, 1.30–1.35 times as broad as long; punctation of lateral portions extremely fine, barely visible, and very sparse; median and posterior dorsal portions extensively impunctate; interstices without microsculpture. Eyes enormous, nearly reaching posterior margin, and strongly bulging. Antenna ( Fig. 18 View Figs 1–26 ) sexually dimorphic, 1.3–1.4 mm long in male and 1.1–1.2 mm long in female, distinctly incrassate, and distinctly asymmetric; antennomere IV moderately transverse; antennomeres V–X of gradually and distinctly increasing width, increasingly asymmetric, and increasingly transverse, more transverse in female than in male; X approximately twice as wide as long; XI elongate, longer (male) or shorter (female) than the combined length of VIII–X.

Pronotum ( Fig. 49 View Figs 40–53 ) moderately transverse, approximately 1.25 times as broad as long and 1.05–1.10 times as broad as head, moderately strongly convex in crosssection; posterior angles obsolete; disc with a median pair of punctures, otherwise practically impunctate; lateral margins each with (probably) four long and erect black setae.

Elytra ( Fig. 49 View Figs 40–53 ) approximately 0.7 times as long as pronotum; suture distinctly gaping posteriorly; punctation sparse and very fine; pubescence long and pale. Hind wings fully developed. Metatarsomere I approximately as long as the combined length of II and III.

Abdomen: paratergites strongly elevated and sharply edged; tergites III–VI each with two lateral setiferous punctures on either side, tergite VI additionally with four setiferous punctures at posterior margin; tergite VII with non-setiferous punctation in posterior two-thirds and with eight setiferous punctures near posterior margin, posterior margin with palisade fringe; tergite VIII ( Fig. 272 View Figs 258–276 ) with two transverse rows of black setae posteriorly and with broadly truncate posterior margin; sternite VIII with broadly, very weakly convex posterior margin.

♂: hemi-tergites IX and tergite X with extremely dense and long pubescence; median lobe of aedeagus ( Figs 269–270 View Figs 258–276 ) 0.68–0.72 mm long and of distinctive shape; internal sac without strongly sclerotized structures; paramere ( Fig. 271 View Figs 258–276 ) approximately 0.55 mm long, with apically hooked paramerite of modified shape and with condylite of strongly reduced size.

♀: abdominal segments IX–X of similar shape and chaetotaxy as in O. hauseri ; spermatheca as in Fig. 273 View Figs 258–276 .

Comparative notes: Based on the modifications of the abdominal segments IX–X, the shape and chaetotaxy of tergite and sternite VIII, and on the morphology of the aedeagus, O. reductus belongs to the O. hauseri group. It is characterized especially by the enormous eyes, by the shape and pronounced sexual dimorphism of the antennae, the shape of the median lobe of the aedeagus, and the derived shape of the paramere.

Distribution and natural history: This species is currently known from two localities in Phongsaly and Louang Phrabang provinces, North Laos. The specimens were collected at altitudes of 1200 and approximately 1500 m, together with O. lunatus , O. nigrapicalis , O. grandicollis , O. extensus , O. serratus , O. bicuspis , O. vates , O. baccillatus , and two unnamed species.