Orphnebius bakeri BERNHAUER, 1929

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 : 50

Orphnebius bakeri BERNHAUER, 1929

( Figs 4, 26 , 223–225 )

Material examined: Indonesia: 1 ♂, 1 ♀, Borneo, Kalimantan Tengah, confluence of Busang and Rekut , 0°03'S, 113°59'E, flight interception trap, VIII.2001, leg. Brendell & Mendel ( BMNH) .

Comment: Orphnebius bakeri is the type species of the subgeneric name Mesocephalobius BERNHAUER, 1929, which was synonymized with Orphnebius by PACE (2007) and revalidated by HLAVÁČ et al. (2011). The original description is based on type material from Singapore. PACE (2007) designated a lectotype and illustrated the median lobe of the aedeagus.

Redescription: Body length 4.0– 4.2 mm; length of forebody 1.7 mm. Coloration: head blackish; pronotum blackish-brown; elytra brown, with the postero-lateral portions slightly and diffusely darker; abdomen palereddish; legs dark-yellowish; antennae blackish, with antennomeres I–IV reddish; maxillary palpi yellowish.

Head ( Fig. 26 ) of transversely oval shape; posterior angles obsolete; dorsal surface with scattered very fine punctures laterally; median and posterior dorsal portions extensively impunctate; interstices without microsculpture. Eyes large, reaching posterior margin of head, much longer than distance from posterior margin of eye to posterior constriction of head in dorsal view. Antenna ( Fig. 4 ) 1.1–1.2 mm long, distinctly incrassate and asymmetric; antennomere IV small and weakly transverse; antennomere V much larger than IV and asymmetric; V–X of gradually increasing width, increasingly transverse, and increasingly asymmetric; XI approximately as long as the combined length of VIII–X.

Pronotum ( Fig. 26 ) 1.2 times as broad as long and 1.00– 1.05 times as broad as head, broadest near anterior angles, strongly convex in cross-section; posterior angles weakly marked; disc with a median pair of punctures and some punctures near lateral margins, otherwise impunctate.

Elytra ( Fig. 26 ) approximately 0.8 times as long as pronotum; punctation sparse and fine; pubescence long, pale, and sub-erect. Hind wings fully developed. Metatarsomere I slightly shorter than the combined length of II and III.

Abdomen: tergite VII with dense, oblong, non-setiferous punctation in posterior three-fourths, near posterior margin with six oblong tubercles, posterior margin with palisade fringe; tergite VIII and sternite VIII with convex posterior margins.

♂: segments IX–X distinctly modified (of the O. hauseri type), with dense and long pubescence; median lobe of aedeagus ( Fig. 223 ) conspicuously large and massive, approximately 1.0 mm long, with small ventral process of distinctive shape; internal sac with several small, strongly sclerotized structures; parameres ( Fig. 224 ) much shorter than median lobe, approximately 0.55 mm long; condylite very slender and slightly longer than paramerite.

♀: spermatheca ( Fig. 225 ) strongly sclerotized and with long proximal portion.

Comparative notes: This species is characterized particularly by the distinctive male sexual characters.

Distribution: Orphnebius bakeri is currently known from Singapore and Borneo ( Malaysia: Sabah; Brunei) ( BERNHAUER 1929, PACE 2007, and material examined).

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 216–235.Orphnebiusfuscapicalis(216–219),O. nigrapicalis(220–222),O. bakeri(223–225),O. breviceps (226–228),O. dilatatus (229–232), and O. extensus (233–235): median lobe of aedeagus in lateral and in ventral view (216–217, 220–221, 223, 226–227, 229–230, 233–234); paramere (218, 222, 224, 228, 231, 235); apex of paramere (219); spermatheca (225, 232). Scale bars: 0.2 mm.