Platystethus tian Zheng, 2000

Lü, Liang & Zhou, Hong-Zhang, 2015, Review of the Genus Platystethus Mannerheim (Coleoptera: Staphylinidae: Oxytelinae) in China, Zootaxa 3915 (2), pp. 151-205 : 190-191

11. Platystethus tian Zheng, 2000

( Figs. 25 ; 26; 27)

Zheng, 2000: 113 (Type locality: Mt. Emei, Sichuan, 1752m, 26.VII.1983); Smetana, 2004: 519 (subgenus Craetopycrus ); Yan, Li & Zheng, 2012: 342, 343.

Material examined. 2 specimens. CHINA: Sichuan: 1♂, Mianningxian [=Mianning Co.], Yele Nature Reserve [28.92ºN 102.23ºE], 2690 m, “No. 60” [in Chinese], 2005. VII.23, F. Xiao leg. ( CWNU); 1♀, Mt. Emei, Xian Feng Temple [29.55ºN 103.35ºE]—Jiu Lao Cave, 1983. VII.26, “II-134”, “Gou, Wang, Xie” [surnames of three collectors] legg. ( CWNU). [Note: these specimens are not types but identified by Prof. Zheng, though the identification information was written in the stopper and tape of containing vials (see above).]

Redescription. Body ( Fig. 26 A, B) shiny; head, antennae, mandibles, pronotum black; maxillae, maxillary palpi, elytra, abdomen, and legs reddish black. Length [average]: ♂, 5.75 mm; ♀, 4.5 mm.

Male. Head ( Figs. 25 A; 26C) broadest at temples. Disc less pubescent, with punctures large and clustered, no micro-striae. Clypeus with surface delicate and not punctate, protruding beyond anterior border of supra-antennal ridges, anterior margin truncate and slightly protruding in middle. Epistomal suture fine and posteriorly directed. Supra-antennal ridges elevated. Vertex depressed anteriorly, without mid-longitudinal suture, with two puncture lines a little behind occipital suture. Eyes slightly convex, shorter than temples, with fine facets; orbital sulcus fine. Temple slightly dilated laterally. Neck constricted, and demarcated by occipital suture. Occipital suture with lateral portions feeble. Labrum with narrow and deep incision in middle of anterior margin ( Fig. 26 C). Mandible ( Fig. 27 A) stout and incurved; bearing 2–3 teeth on inner edge.

Pronotum ( Figs. 25 A; 26C) wider than or equal with head, widest at anterior 1/3, with mid-longitudinal sulcus and micro-striae absent, with a few finely punctate depressions beside middle zone; anterior margin broadly emarginate, anterior lateral angles prominent, posterior angles very prominent; lateral and posterior margins without crenulation, near lateral margin with shallow punctate depression. Scutellum with crest-shaped impression. Elytra ( Fig. 26 A) densely punctate and micro-striate on disc; posterior margin obliquely truncate or truncate, elytral suture not overlapping.

Abdominal sternite VII ( Figs. 25 C; 27C) with posterior margin crescently emarginate in middle, where with membrane (not beyond posterior margin). Sternite VIII ( Figs. 25 D; 27D) posterior margin broadly rounded and shallowly emarginate in middle, with two small processes near middle, behind which situated with two short spinules; subbasal ridges continuous in middle.

Aedeagus ( Figs. 25 G–J; 27G–K) with median lobe ovoid; apical orifice fissure-like, reaching apical 1/4 of ventral surface, edges of ventral fissure protruding into a pair of sharp triangular spines; internal sac with scleritelike and membranous parts, not rolling. Paramere arm-like; basal arm with furrow; apical arm slightly explanate at apex, furnished with setae at apex, with another seta near apex of ventral edge, by which a few pits lined.

Female. Head ( Figs. 25 B; 26D) smaller than male, punctures sparsely scattered. Mandibles smaller ( Fig. 27 B). Pronotum ( Figs. 25 B; 26D) a little wider than head, with anterior margin straight. Abdominal sternite VII without modification, sternite VIII ( Figs. 25 E; 27E) gradually narrowed, with posterior margin rounded.

Spermatheca ( Figs. 25 F; 27F) constricted at middle, basal part inflated; apical part curved and slightly broaden at apex.

Distribution. China (Guizhou, Sichuan).

Figures

FIGURE 25. Platystethus tian Zheng, 2000 I: A, head and pronotum ♂ (dorsal view); B, head and pronotum ♀ (dorsal view); C, sternite VII ♂; D, sternite VIII ♂; E, sternite VIII ♀; F, spermatheca; G, median lobe of aedeagus (ventral view); H, median lobe (lateral view); I, right paramere (in situ) of aedeagus (ventral view); J, right paramere (in situ, ventro-lateral view). Scales: A, B = 0.5 mm; F = 0.05 mm; rest, 0.2 mm.

FIGURE 26. Platystethus tian Zheng, 2000 II: A, habitus ♂; B, habitus ♀; C, head and pronotum ♂ (dorsal view); D, head and pronotum ♀ (dorsal view). Scales: 0.5 mm.

FIGURE 27. Platystethus tian Zheng, 2000 III: A, right mandible ♂; B, right mandible ♀; C, sternite VII ♂; D, sternite VIII ♂; E, sternite VIII ♀; F, spermatheca; G, aedeagus (ventral view); H, aedeagus (dorsal view); I, median lobe of aedeagus (ventral view); J, median lobe of aedeagus (lateral view); K, right paramere (in situ) of aedeagus (lateral view). Scales: F = 0.05 mm; rest, 0.3 mm.