Lobrathium circumclusum, Assing, 2014

Assing, V., 2014, A revision of Palaearctic Lobrathium. V. Three new species from the Himalaya and China, a new synonymy, and additional records (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 46 (1), pp. 429-441 : 438-440

Lobrathium circumclusum nov.sp. ( Figs 17-21 )

T y p e m a t e r i a l: Holotype 6: "Burma, Taunggyi, 1:I:1980, de Rougemont / Holotypus 6 Lobrathium circumclusum sp. n., det. V. Assing 2013" (cRou). Paratype 6: " BURMA, Taunggyi, 8:III:1981, de Rougemont " (cAss).

E t y m o l o g y: The specific epithet (Latin, adjective: enframed) alludes to the chaetotaxy of the male sternite VII, whose postero-median impression is enframed by modified setae.

D e s c r i p t i o n: Body length 7.5-8.5 mm; length of forebody 4.3-4.5 mm. Coloration: forebody black; elytra with or without dark-bluish hue, with large circular yellowish spot posteriorly, this spot leaving the posterior, lateral, and sutural margins narrowly blackish; abdomen blackish; legs blackish-brown to black, with the middle of the meso- and metafemora more or less distinctly paler (dark-yellowish to yellowishbrown); antennae blackish-brown to blackish, with the basal and/or the apical antennomeres somewhat paler.

Head ( Fig. 17 ) approximately as broad as long; lateral margins broadly rounded towards posterior constriction; punctation moderately coarse, somewhat umbilicate, and very dense, except for a transverse impunctate or sparsely punctate glossy area in median dorsal portion and a longitudinal impunctate glossy area on frons. Eyes large, 0.6-0.7 times as long as distance from posterior margin of eye to neck. Antenna approximately 2.6 mm long.

Pronotum ( Fig. 17 ) approximately 1.25 times as long as broad and 0.9 times as broad as head; punctation as coarse as that of head, but less dense; interstices on average narrower than diameter of punctures; impunctate midline moderately broad.

Elytra ( Fig. 17 ) approximately as long as pronotum; punctation dense, irregular, and much coarser than that of head and pronotum. Hind wings present. Protarsomeres I-IV strongly dilated.

Abdomen approximately 0.9 times as broad as elytra; punctation fine and moderately dense, distinctly coarser in the distinct anterior impressions of tergites III-V; interstices with fine and shallow transverse microsculpture; posterior margin of tergite VII with palisade fringe.

6: tergite VIII with weakly convex posterior margin; sternite VII ( Fig. 18 ) distinctly transverse and with pronounced postero-median impression of sub-circular shape, this impression without setae, but enframed by relatively few strongly modified short and stout black setae, posterior margin broadly concave; sternite VIII ( Fig. 19 ) approximately as long as broad and with pronounced longitudinal median impression, this impression with numerous strongly modified short and stout black setae anteriorly and laterally, and without any setae in postero-median portion, posterior excision rather broad, deep, and of subtrapezoid shape, on either side of excision with dense modified short and stout black setae; aedeagus approximately 1.25 mm long; ventral process blade-shaped, broadest approximately in the middle in ventral view, and with numerous ventral teeth; dorsal plate almost completely reduced; internal sac with pair of dark structures.

♀: unknown. C o m p a r a t i v e n o t e s: As can be inferred from the similarly derived shapes and chaetotaxy of the male sternites VII and VIII, as well as from the similar morphology of the aedeagus, L. circumclusum is closely allied to the geographically close L. guttula , to L. sinuatum ASSING 2012 from China, and to L. kleebergi ASSING 2012 from Nepal. It is distinguished from them by the number and arrangement of the modified setae on the male sternites VIII, by the shape and chaetotaxy of the posterior excision of the male sternite VIII (deeper and less broad than in L. guttula ; anterior margin not distinctly bisinuate and without modified setae), and by the shape of the ventral process of the aedeagus (in L. guttula widest near base in ventral view and apically less slender in lateral view). For illustrations of L. guttula , L. kleebergi, and L. sinuatum see ASSING (2012).

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y:Thetypelocalityissituatedin central Myanmar. Additional data are not available.

Figures

Figs 17-21: Lobrathium circumclusum nov.sp.: (17) forebody; (18) male sternite VII; (19) male sternite VIII; (20-21) aedeagus in lateral and in ventral view. Scale bars: 17: 1.0 mm; 18-21: 0.5 mm.