Lobrathium biuncinatum, Assing, 2017

Assing, Volker, 2017, A revision of Palaearctic Lobrathium. VI. Two new species from Armenia and Taiwan, and additional records (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 49 (1), pp. 299-306 : 304-305

Lobrathium biuncinatum nov.sp. ( Figs 8-11 )

T y p e m a t e r i a l: Holotype 3: " Taiwan, Taitung Hsien, Hsinkangshan above Chengkang 750 m 21.IV.1998 A. Smetana [T185] / Holotypus 3 Lobrathium biuncinatum sp.n., det. V. Assing 2015" (cAss) . Paratypes: 1♀ [teneral]: same data as holotype (cSme) ; 1♀: same data, but " 18.IV.1998 ... [T182]" (cAss) ; 1♀: same data, but " 800 m 27.IV.1995 ... [T168]" (cSme) .

E t y m o l o g y: The specific epithet (Latin, adjective: with two hooks) alludes to the shape of the apex of the aedeagus.

D e s c r i p t i o n: Large species; body length 8.8-10.0 mm; length of forebody 5.1- 5.5 mm. Coloration: body blackish-brown; legs: forelegs dark-brown with reddish tarsomere V, mid- and hindlegs dark-yellowish with dark-brown tibiae; antennae basally blackish-brown, gradually becoming paler towards apex, apical antennomeres reddish.

Head ( Fig. 8 ) approximately as broad as long and of subcircular shape, posterior angles obsolete; punctation very dense, moderately coarse, and umbilicate. Eyes approximately as long as, or slightly longer than, distance from posterior margin of eye to posterior constriction of head. Antenna approximately 3.2 mm long.

Pronotum ( Fig. 8 ) 1.15-1.18 times as long as broad and approximately as broad as head; punctation slightly less dense, less distinctly umbilicate, and coarser than that of head; impunctate median band narrow, extending to anterior and posterior margins, or nearly so.

Elytra ( Fig. 8 ) approximately 0.7 times as long as pronotum; humeral angles marked; lateral parts with fine submarginal line; punctation coarse and partly arranged in very irregular, oblique, confluent rows; interstices without microsculpture.

Abdomen slightly broader than elytra; punctation dense; interstices with fine and shallow microreticulation; posterior margin of tergite VII without palisade fringe.

3: posterior margin of tergite VIII indistinctly angled in the middle; sternites V-VI without impressions; sternite VII with weakly concave posterior margin; sternite VIII ( Fig. 9 ) with shallow oblong postero-median impression, without peg-setae, posterior excision

0.22 times as deep as length of sternite; aedeagus ( Figs 10-11 ) apically with a pair of hook-shaped processes.

♀: tergite VIII posteriorly acutely angled in the middle.

C o m p a r a t i v e n o t e s: Based on the external and male sexual characters, L. biuncinatum belongs to the lineage including L. stimulans and related species, all of which are locally endemic in Taiwan. It is distinguished from them particularly by the shape of the apex of the aedeagus. For illustrations of the Lobrathium species previously known from Taiwan see ASSING (2010).

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: The type specimens were collected in two close localities in Hsinkang Shan, Taitung Hsien, Taiwan, at altitudes of 750 and 800 m. They were sifted from leaf litter and other debris along walls of an abandoned forest road (T182, T185) and from wet leaf litter and debris at the base of a vertical rockwall (T168) (SMETANA pers. comm.).

Figures

Figs 8-11: Lobrathium biuncinatum nov.sp.: (8) forebody; (9) male sternite VIII; (10-11) aedeagus in lateral and in ventral view. Scale bars: 8: 1.0 mm; 9-11: 0.5 mm.