Orphnebius latitibialis, 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 : 54-55

Orphnebius latitibialis spec. nov.

( Figs 29, 38 , 251–252 )

Type material: Holotype ♀ [antennomere XI of left antenna and antennomeres IV–XI of right antenna missing]: “ Laos-N ( Louangphrabang ), 11–21.v.2002, 19°35'N, 101°58'E, Thong Khan , ~ 750 m, Vít Kubáň leg. / Holotypus ♀ Orphnebius latitibialis sp. n., det. V. Assing 2015” ( NHMB).

Etymology: The specific epithet (Latin, adjective) alludes to the conspicuously dilated mesotibiae.

Description: Body length 4.3 mm; length of forebody 2.0 mm. Coloration: forebody black; abdomen red; legs with blackish-brown femora and mesotibiae, dark-brown pro- and metatibiae, and reddish tarsi; antennae blackish with antennomeres I–IV reddish-brown; maxillary palpi yellowish-red with the apical palpomere yellowish.

Head ( Fig. 29 ) of transversely rectangular shape, 1.48 times as broad as long (length measured from sclerotized portion of clypeus); posterior angles moderately marked; posterior margin weakly concave in the middle; clypeus extensively membranous; dorsal surface nearly impunctate. Eyes large, more than twice as long as postocular region in dorsal view. Antennomere I approximately as long as the combined length of antennomeres II and III; antennomere IV moderately transverse and flattened; antennomere V much broader than antennomere IV; antennomeres V–X distinctly asymmetric, moderately flattened, and strongly transverse, more than twice as broad as long, and gradually increasing in width.

Pronotum ( Fig. 29 ) 1.3 times as broad as long and 1.06 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 practically impunctate; lateral margins with three long, erect, brown setae.

Elytra ( Fig. 29 ) approximately 0.7 times as long as pronotum; punctation sparse and fine; pubescence long, fine, pale, and depressed to sub-erect. Hind wings fully developed. Mesotibia ( Fig. 38 ) strongly dilated, covered with dense setiferous tubercles, posterior surface with large, long, and deep excavation without such tubercles. Metatarsomere I approximately as long as the combined length of II and III.

Abdomen:tergites III–VI with a lateral setiferous puncture on either side, III–IV with an additional pair of setiferous punctures at or near posterior margin, and V–VI with four additional punctures at posterior margin; tergite VII with dense slightly oblong non-setiferous punctures in posterior three-fourths, posterior margin with palisade fringe; tergite VIII ( Fig. 252 ) with a postero-median pair of long black setae, with three lateral long black setae in posterior portion, and with a lateral cluster of fine setae on either side, posterior margin convex and with eight short teeth; sternite VIII with broadly convex posterior margin.

♂: unknown.

♀: segments IX–X distinctly modified (of the O. hauseri type), with dense and long pubescence; spermathecal capsule with very long and thin proximal portion ( Fig. 251 ).

Comparative notes and comment: Based on the external and sexual characters, O. latitibialis belongs to the O. serratus subgroup sensu strictu. The similar shape and chaetotaxy of tergite VIII, as well as the modified mesotibiae suggest that it is closely allied to O. integer . The species is readily distinguished from all its congeners by the conspicuously modified mesotibiae alone, so that a description based on a female seems justified.

Distribution and natural history: The type locality is situated in Louangphrabang province, North Laos, at an altitude of approximately 750 m. Orphnebius dilatatus , O. extensus , O. serratus , O. bicuspis , O. retunsus , O. cultellatus , and O. carinatus were collected in the same locality.

Figures

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 236–257. Orphnebius serratus (236–243), O. integer (244–250), O. latitibialis (251–252), and O. bicuspis from Laos (253– 257): median lobe of aedeagus in lateral and in ventral view (236–237, 244–245, 253–254); apex of median lobe in ventral view (238, 246, 255); paramere (239, 247, 256); tergite VIII (240, 249, 252); spermatheca (241–243, 251, 257); apex of paramerite (248); postero-median portion of tergite VIII (250). Scale bars: 0.2 mm.