Orphnebius taurus, Assing, 2019

Assing, Volker, 2019, On the Lomechusini fauna of the Palaearctic and Oriental regions. XXVI. New species, a new synonymy, and additional records (Coleoptera: Staphylinidae: Aleocharinae), Beiträge Zur Entomologie = Contributions to Entomology 69 (1), pp. 33-70 : 48-49

Orphnebius taurus spec. nov.

urn:lsid:zoobank.org:act:9C47DCE3-7D9A-4D71-8A4B-24036B41A66D

( Figs 3–5 , 91–95 )

Type material: Holotype: “SW Cambodia, 20 km SE Koh Kong, 50–300 m, 3.–19.v.2005, Tatai river , 11°34'N, 103°07'E, E. Jendek & O. Šauša leg. / Holotypus Orphnebius taurus sp. n., det. V. Assing 2018” ( MMB).

Etymology: The specific epithet (Latin: bull) is a noun in apposition and alludes to the two long horn-shaped processes of the mandibles.

Description: Small species; body length 3.0 mm; length of forebody 1.4 mm. Habitus as in Fig. 3 . Coloration: head blackish with the anterior portion brown; pronotum pitchy-black; elytra yellowish-brown with the scutellar portion diffusely darker; abdomen pale yellowish-brown; legs yellowish-brown with dark-yellowish tarsi; antennae dark-brown with antennomeres II–V reddish; maxillary palpi brown with the apical palpomere yellow.

Head ( Figs 4–5 ) strongly transverse, in the middle of dorsal surface with pronounced tubercle-shaped elevation; both mandibles with a long and erect horn-shaped process originating from their bases (male secondary sexual character?). Eyes very large, longer than distance from posterior margin of eye to posterior constriction of head. Antenna approximately 1.0 mm long, distinctly incrassate apically, and somewhat clavate, with antennomeres VI–X much larger than antennomeres II–V; antennomere I large, long, and distinctly compressed, nearly as long as the combined length of antennomeres II–V; antennomeres VI–X strongly transverse and distinctly asymmetric; antennomere XI approximately as long as the combined length of antennomeres VIII–X.

Pronotum strongly transverse and rather small in relation to head, approximately 1.65 times as broad as long and approximately as broad as head, moderately convex in cross-section; posterior angles obsolete; disc impunctate; lateral margins each with three long and stout darkbrown setae.

Elytra approximately 0.8 times as long as pronotum, strongly widened posteriad; punctation sparse and fine. Hind wings fully developed. Metatarsomere I approximately as long as the combined length of II and III.

Abdomen broad, gradually tapering from base towards apex; segments III–VI with broad and dorsally truncate paratergites; tergites III–VI practically impunctate; tergite VII with dense and long striae except near anterior margin; tergite VIII laterally with a cluster of dense thin setae on either side, posterior margin broadly convex.

: hemi-tergites IX and tergite X with dense and long pubescence; sternite VIII as in Fig. 91 ; median lobe of aedeagus ( Figs 92–94 ) 0.65 mm long and of distinctive shape; ventral process apically acute and conspicuously structured; paramere ( Fig. 95 ) 0.57 mm long, paramerite very slender.

: unknown.

Comparative notes: Based on the large head (in relation to the pronotum) and the slender paramerite, O. taurus is assigned to the O. dilatatus subgroup of the O. hauseri group. Among the species of the O. hauseri group, the new species is characterized particularly by the conspicuous modifications of the (male?) head (median tubercle; two long mandibular processes) and by the shape of the median lobe of the aedeagus.

Distribution and natural history: The type locality is situated near Koh Kong in Southwest Cambodia at an altitude between 50 and 300 m. Additional data are not available.

Figures

Figs 1–15:Myrmoecia urartu (1), Pella feldmanni (2), Orphnebius taurus (3–5), O. fortesetosus (6–7), O. morulus (8–9), O. globifer (10–11), andO. elevatus (12–15): habitus (1–3); head and pronotum (4–5); forebody (6, 8, 10, 12–13); abdomen (7, 9, 11); anterolateral portion of abdomen (14); tergites VII–VIII (15). Scale bars: 1–3: 1.0 mm; 4–15: 0.5 mm.

Figs 79–95: Myrmoecia urartu (79), Pella feldmanni (80–83), Orphnebius cachemiricus (84–86), O. fortesetosus (87–90), and O. taurus(91–95): spermatheca (79); median lobe of aedeagus in lateral and in ventral view (80–81, 84–85, 87–88, 92–93); male tergite VIII (82, 91); male sternite VIII (83); paramere (86, 89, 95); apical portion of paramere (90); apical portion of median lobe of aedeagus (94). Scale bars: 79–93, 95: 0.2 mm; 94: 0.1 mm.