Platystethus erlangshanus Yan, Li & Zheng, 2012

Lü, Liang & Zhou, Hong-Zhang, 2015, Review of the Genus Platystethus Mannerheim (Coleoptera: Staphylinidae: Oxytelinae) in China, Zootaxa 3915 (2), pp. 151-205 : 176-178

6. Platystethus erlangshanus Yan, Li & Zheng, 2012

( Figs. 14 & 15)

Yan, Li & Zheng, 2012: 341, 342 (Type locality: Sichuan, Tianquan County ([Mt. Erlang], 29 º 49 ' – 30 º 13 ' N, 102 ºl 7 ' – 102 º 37 ' E; alt. 2800 m), cow dung).

Material examined. 5 specimens, 4 ♂♂, 1 ♀♀. CHINA: Sichuan: 1 ♂, Baoxing, Guobayan [30.64 ºN 102.83 ºE], 3340 m, alpine meadow, pitfall trap, 2001. VII. 1–4, X.-D. Yu & H.-Z. Zhou legg. (IZ-CAS); 1 ♀, same data as previous except: 3270 m, Abies forest (IZ-CAS); 1 ♂, Baoxing, Mahuanggou [30.81 ºN 102.73 ºE], 2681m, pitfall trap, 2012. VI. 29, H.-L. Shi & Y. Liu legg. (IZ-CAS); 1 ♂, Ganzi [=Garze], Moxizhen [=Moxi Township], Changheba [30.26 ºN 102.19 ºE], sifting, 2009. V. 19, Y.-L. Zhou leg. (IZ-CAS); 1 ♂, Wolong, Mt. Balang [30.90 ºN 102.92 ºE], 3700m, alpine meadow, pitfall trap, 2004. VII. 5–8, X.-D. Yu leg. (IZ-CAS).

Redescription. Body black; mandibles, maxillary palpi, apical 4 antennomeres reddish brown; elytra and legs light brown to yellow, darker in margins. Length [average]: ♂, 4.5 mm; ♀, 4.2 mm.

Male. Head ( Figs. 14 A; 15 A) broadest at temples. Disc nearly glabrous, with punctures dense and coarse. Clypeus transverse, with anterior margin slightly emarginate, in middle furnished with short sharp process, bordered with membrane at each side. Epistomal suture with middle portion absent, lateral portions short and obscure and posteromedially directed. Supra-antennal ridges obviously elevated. Vertex depressed weakly coriaceous, glabrous, barely punctate in anterior part, convex and strongly punctate at each side of mid-longitudinal suture; mid-longitudinal suture short and deep, posteriorly reaching occipital suture. Eyes slightly convex, shorter than temples, with fine facets; orbital sulcus fine. Temple dilated laterally. Occipital suture deep and arciform, with large setal fovea at each end. Mandible ( Fig. 15 C) stout, and dull and incurved at apex; bearing 3 reduced teeth on inner edge: 2 large with 1 tiny in between; with tiny spur situated in fovea at middle of dorsal surface.

Pronotum ( Figs. 14 A; 15 A) as wide as head or narrower, widest at anterior 1 / 3, with mid-longitudinal sulcus throughout, with punctures sparser and smaller than in head, without micro-striae; anterior margin bi-emarginate, anterior lateral angles produced, no posterior angles; lateral and posterior margins integrated and evenly rounded, with marginal bead broad, without crenulation. Scutellar impression heart-shaped, anterior margins crescent. Elytra ( Fig. 15 A) with posterior margin obliquely truncate, elytral suture dehiscent.

Abdomen weakly coriaceous. Sternite VII ( Figs. 14 C; 15 E) with posterior margin prominently and rectangularly protruding in middle. Sternite VIII ( Figs. 14 D; 15 F) tri-partitioned by 2 curved narrow sutures, middle part with posterior margin a little curved and with mid-longitudinal internal ridge at anterior 2 / 3, lateral parts completely separated by middle part, each at mesial side with long process (longer than that in P. arenarius but shorter than in P. burcerus ) situated with short seta at apex; basal ridge interrupted in middle, sub-basal ridge with middle portion absent.

Aedeagus ( Figs. 14 G–I; 15 I –L) with median lobe bottle-like, inflated at base; apical orifice large and broadly fissured to middle of ventral surface, embedded with sharp triangular sclerite there, edges of ventral fissure dully protruding, incrassated, and sparsely pubescent; internal sac membranous. Paramere arm-like, basal arm with furrow on ventral surface; apical arm furnished with two slender setae: one at apex, the other nearing apical 1 / 3, with pits scattered along ventral edge.

Female. Head ( Figs. 14 B; 15 B) smaller, narrower than pronotum; clypeus longer, slightly protruding in middle of anterior margin which entirely beyond supra-antennal ridges; epistomal suture with lateral portion longer and obvious; vertex slightly convex at side of mid-longitudinal suture; eyes convex, nearly equal to temples in length, temples not dilated. Mandibles ( Fig. 15 D) shorter than in male, with teeth more prominent. Pronotal anterior margin ( Figs. 14 B; 15 B) with bi-emargination weaker. Abdominal sternite VII with posterior margin straight. Sternite VIII ( Figs. 14 E; 15 G) not partitioned, without processes, with posterior margin broadly rounded and a little protruding in middle.

Spermatheca ( Figs. 14 F; 15 H) clavate, with basal part inflated into globoid and apical part slender and reversely hooked at apex.

Distribution. Sichuan.