Rugilus (Rugilus) rugosissimus, Assing, 2015

Assing, Volker, 2015, A revision of Palaearctic and Oriental Rugilus. V. Two new species from China and additional records (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 47 (1), pp. 73-82 : 78-80

Rugilus (Rugilus) rugosissimus nov.sp. ( Figs 6-10 )

T y p e m a t e r i a l: Holotype 3: " CHINA, Guizhou, Fanjing Shan , 27°54'N, 108°42'E, 1400-1700 m, 5.-11.VI.2014, leg. C. Reuter / Holotypus 3 Rugilus rugosissimus sp. n., det. V. Assing 2014 " (cAss).

E t y m o l o g y: The specific epithet is the superlative of the Latin adjective rugosus and alludes to the conspicuously rugosely confluent punctation of the head and pronotum.

D e s c r i p t i o n: Body length 7.2 mm; length of forebody 4.1 mm. Coloration: head, pronotum, and abdomen blackish-brown; elytra dark-brown with slight bronze hue; forelegs reddish; mid- and hindlegs dark-yellowish, with the femoral apices indistinctly infuscate; antennae with blackish-brown base, apically gradually becoming paler brown.

Head ( Fig. 7 ) distinctly tranverse, 1.17 times as broad as long, broadest across eyes; margins behind eyes smoothly and weakly curving towards posterior constriction in dorsal view, posterior angles weakly marked; punctation coarse, largely longitudinally confluent, less confluent and noticeably umbilicate only on frons. Eyes large and moderately convex, approximately 0.7 times as long as distance from posterior margin of eyes to posterior constriction. Anterior margin of labrum with two pronounced, basally fused teeth on either side of the narrow median incision.

Pronotum ( Fig. 7 ) 1.13 times as long as broad and 0.7 times as wide as head; midline without impunctate, glossy band; punctation similar to that of head.

Elytra ( Fig. 6 ) 0.75 times as long as pronotum; punctation dense, coarse, and defined; interstices glossy. Hind wings apparently reduced. Metatarsomere I nearly as long as the combined length of II and III.

Abdomen approximately as broad as elytra; tergites III-VI with shallow impressions anteriorly, these impressions with coarse and dense punctation; punctation of remaining tergal surfaces fine and dense; interstices without distinct microsculpture; posterior margin of tergite VII without palisade fringe.

3: sternite VII ( Fig. 8 ) strongly transverse, approximately 1.55 times as broad as long, with shallow median impression, posterior margin with pronounced, nearly semi-circular excision; sternite VIII ( Fig. 9 ) approximately 1.15 times as broad as long, posterior excision convex anteriorly and 0.2 times as deep as length of sternite; aedeagus small in relation to body size, 0.66 mm long, and of robust shape ( Fig. 10 ).

C o m p a r a t i v e n o t e s: Based on the similarly derived modifications of the male sternite VII (with large and nearly semi-circular posterior excision), the similarly derived morphology of the aedeagus (small, but robust; ventral process short and forming an angle with the basal portion; internal sac with large black sclerites), as well as the similar external characters, R. rugosissimus is undoubtedly most closely related to R. wuyicus ASSING, 2012 from Jiangxi, R. desectus ASSING, 2012 from Yunnan, R. aquilinus ASSING, 2012 from Sichuan, and R. malaisei (SCHEERPELTZ, 1965) from Burma. It is distinguished from all of them by the conspicuous longitudinal rugae on the head and pronotum and by the slightly different shape of the aedeagus. In addition it differs from them as follows:

from R. wuyicus by the larger and more transverse head with relatively smaller eyes, broader elytra, the slightly deeper and less broad posterior excision of the male sternite VII, the deeper posterior excision of the male sternite VIII, by the more pronounced ventral projection at the base of the ventral process of the aedeagus (lateral view), and by the slightly different shape of the apex of the ventral process (lateral view);

from R. malaisei by the larger and more transverse head, the more slender and more oblong pronotum (R. malaisei: approximately as broad as long), the smaller posterior excision of the male sternite VII, the narrower posterior excision of the male sternite VIII, and by the apically less acute and more truncate ventral process of the aedeagus;

from R. desectus by the relatively larger and more transverse head with completely obsolete posterior angles, the more slender and more oblong pronotum, much shorter and narrower elytra, the distinctly smaller and sub-circular posterior excision of the male sternite VII, the less distinctly V-shaped posterior excision of the male sternite VIII, and by the much smaller aedeagus with a much more slender ventral process (lateral view);

from R. aquilinus by the relatively larger and more transverse head with completely obsolete posterior angles and a longer postocular region in relation to the eyes, the distinctly more massive antennae, the shorter male elytra, and the somewhat less strongly curved ventral process of the aedeagus (lateral view).

For illustrations of the external and male sexual characters of R. wuyicus , R. desectus , and R. malaisei see ASSING (2012a, 2012b).

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 locality is situated in the Fanjing Shan, a somewhat isolated mountain range in the northeast of Guizhou, South China. The holotype was collected at an altitude between 1400 and 1700 m. Additional data are not available.

Figures

Figs 6-10: Rugilus rugosissimus nov.sp.: (6) forebody; (7) head and pronotum; (8) male sternite VII; (9) male sternite VIII; (10) aedeagus in lateral view. Scale bars: 6-7: 1.0 mm; 8-10: 0.5 mm.