Orphnebius breviceps CAMERON, 1946

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 : 50-51

Orphnebius breviceps CAMERON, 1946

( Figs 5 , 30 , 226–228 )

Orphnebius (Megabocephalobius) breviceps CAMERON, 1946: 691 f.

Orphnebius vorax PACE, 2000: 71 ff.; syn. nov.

Type material: Holotype ♂: “62251 / Siam, Renong / Doherty / Orphnebius breviceps Cam. Type / Fry Coll. 1905.100. / Type / Holotypus ♂ Orphnebius breviceps Cameron , rev. V. Assing 2015” ( BMNH).

Comment: The original description of O. breviceps is based on a unique male from “ Siam: Renong” ( CAMERON 1946), that of O. vorax on an incomplete male and two females from “ Thailand, River Kwae Ban Sai Yok” ( PACE 2000). The aedeagus of the holotype of O. breviceps is identical to that figured by PACE (2000) for O. vorax , which leads to the conclusion that both names refer to the same species. The below redescription is based on the holotype of O. breviceps .

Redescription: Small species; body length 2.7 mm; length of forebody 1.3 mm. Coloration: head and pronotum blackish-brown; elytra yellowish-brown, with the posterolateral portions extensively dark-brown; abdomen pale-reddish; legs reddish-brown; antennae dark-brown, with antennomeres II–V reddish and I reddish-brown; maxillary palpi brown with yellowish palpomere IV.

Head ( Fig. 30 ) distinctly wedge-shaped and strongly transverse; punctation fine and very sparse; median and posterior dorsal portions extensively impunctate; interstices without microsculpture. Eyes large and strongly bulging, reaching posterior margin of head, much longer than distance from posterior margin of eye to posterior constriction of head in dorsal view. Antenna ( Fig. 5 ) 1.0 mm long, distinctly incrassate; antennomere I approximately as long as the combined length of II–V; antennomere IV small and approximately as long as broad; antennomere V slightly less small than IV and moderately transverse; antennomere VI much larger, broader, and more transverse than V; antennomeres VI–X approximately twice as broad as long (or nearly so) and asymmetric; antennomere XI slightly longer than the combined length of IX and X.

Pronotum ( Fig. 30 ) 1.59 times as broad as long and 0.95 times as broad as head, moderately convex in crosssection; lateral and posterior margins together nearly forming a semi-circle, posterior angles completely obsolete; disc with a median pair of punctures, otherwise impunctate.

Elytra ( Fig. 30 ) approximately 0.9 times as long as pronotum; punctation sparse and fine; pubescence long, pale, and sub-erect to erect. Hind wings fully developed. Metatarsomere I approximately as long as the combined length of II and III.

Abdomen:tergite VII predominantly with dense longitudinal striae and additional oblong non-setiferous punctures, near posterior margin with some setiferous punctures, posterior margin with palisade fringe; tergite VIII with two transverse series of long black setae posteriorly, posterior margin convex, in the middle truncate; sternite VIII with broadly convex posterior margin.

♂: segments IX–X distinctly modified (of the O. hauseri type), with dense and long pubescence; median lobe of aedeagus ( Figs 226–227 ) conspicuously slender, 0.7 mm long and of very distinctive shape; ventral process apically hook-shaped in lateral view; paramere ( Fig. 228 ) of highly distinctive shape: paramerite and condylite very slender; paramerite distinctly notched approximately in the middle; condylite nearly as long as paramerite.

♀: spermatheca with very long and coiled proximal portion ( PACE 2000: figure 88).

Comparative notes: Orphnebius breviceps is distinguished from other revised representatives of the O. dilatatus subgroup by the morphology of the antennae, the coloration of the elytra, and especially by the male primary sexual characters.

Distribution: The currently known distribution is confined to two localities in Thailand.

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 27–39. Forebody (27–34), abdomen (35–37), mesotibia (38), and protibia (39) of Orphnebius spp. of the O. hauseri group: fuscapicalis (27, 35), dilatatus (28, 36), latitibialis (29, 38), breviceps (30), extensus (31), serratus (32, 39), integer (33, 37), bicuspis, Laos (34). Scale bars: 27–37: 1.0 mm; 38–49: 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.