Rugilus (Rugilus) atronitidus, Assing, 2013

Assing, V., 2013, A revision of Palaearctic and Oriental Rugilus. III. Five new species from the Palaearctic region and additional records (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 45 (1), pp. 171-190 : 180-181

Rugilus (Rugilus) atronitidus nov.sp.

( Map 1 )

Type material: Holotype ♂: "P. R. China, Yunnan, E slope N Gaoligong Shan, N27°59'01.0'' E098°32'56.9'', 27.v.2010, 3018 m, sifting22, V. Grebennikov / Holotypus ♂ Rugilus atronitidus sp. n., det. V. Assing 2013" ( CAS).

Etymology: The specific epithet (Latin, adjective) refers to the glossy elytra, one of the characters distinguishing this species from R. meilixuensis and R. confluens .

Description: Body length 5.2 mm; length of forebody 3.0 mm. For illustrations of the habitus and the forebody see figures 2-3 in ASSING (2012b). Coloration: body black; legs brown with somewhat darker femora; antennae pale-brown, with antennomeres I and II somewhat infuscate.

Head 1.05 times as broad as long, broadest across eyes; margins behind eyes weakly convex, posterior angles obsolete; dorsal surface somewhat uneven, median dorsal portion transversely elevated, anterior and posterior to this elevation irregularly, transversely impressed; punctation coarse and dense, largely confluent in median dorsal portion; interstices mostly reduced to narrow ridges, but surface with some shine. Eyes large and bulging, approximately 0.7 times as long as distance from posterior margin of eyes to posterior constriction, and with distinct dense and dark pubescence. Anterior margin of labrum with two pronounced, basally fused, and strongly projecting teeth on either side of median incision.

Pronotum 1.15 times as long as broad and approximately 0.7 times as wide as head; punctation dense, coarse, and granulose; midline with short, indistinct, oblong glossy patch posteriorly.

Elytra long and large, approximately 1.12 times as long and 1.5 times as broad as pronotum, and distinctly glossy; punctation dense, moderately fine; interstices without microsculpture. Hind wings fully developed. Metatarsomere I approximately as long as the combined length of II and III.

Abdomen distinctly narrower than elytra; tergites III-VI with shallow impressions anteriorly, these impressions with coarse punctation; punctation of remaining tergal surfaces fine and moderately dense; tergite VII with very shallow, tergites III-VI without appreciable microsculpture; posterior margin of tergite VII with palisade fringe.

♂: sternite VII ( ASSING 2012b: figure 5) distinctly transverse and with broadly concave posterior margin; sternite VIII ( ASSING 2012b: figure 4) with moderately deep, broadly V-shaped posterior excision; aedeagus ( ASSING 2012b: figure 6) 0.61 mm long; ventral process of similar shape as in R. meilixuensis ASSING 2012 .

Comment: The holotype had previously been identified and illustrated as R. meilixuensis , primarily based on the similar shape of the aedeagus ( ASSING 2012b). However, a re-examination of this specimen and of material of R. meilixuensis in the course of a comparative study of the variation of R. confluens revealed that the male from the Gaoligong Shan represents a distinct species.

Comparative notes Rugilus atronitidus is distinguished from R. meilixuensis and R. confluens by the completely black coloration of the body, the distinctly more shiny, less densely and more finely punctate elytra, the more glossy head and pronotum, a shorter head, the denser and more distinct pubescence of the eyes, the more uneven dorsal surface of the head, and by the slightly different shape of the aedeagus.

Distribution and natural history:The type locality is situated in the northern Gaoligong Shan in the northwest of Yunnan province, China, where the holotype was sifted at an altitude of approximately 3020 m. The pronounced wing dimorphism in closely related species suggests that R. atronitidus may be wingdimorphic, too.

Figures

Map 1: Distributions of Rugilus gansuensis ROUGEMONT (triangles), R. confluens ASSING (diamonds), R. meilixuensis ASSING (circles), and R. atronitidus nov.sp. (star), based on examined records. Filled symbols: male-based records; open symbols: female-based records.