Platystethus luae 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 : 178-182

7. Platystethus luae Zheng, 2000

( Figs. 16 ; 17; 18)

Zheng, 2000: 112 (Type locality: Sichuan, Mt. Emei (29.30N 103.20E), 1500m, 1982-VII-30); Smetana, 2004: 518 (subgenus Craetopycrus ); Yan, Li & Zheng, 2004: 342.

Material examined. 4 specimens, 2♂♂, 2♀♀. CHINA: Sichuan: 1♂, Baoxing, Fengtongzhai [30.53ºN 102.91ºE], 1795 m, mixed coniferous broad leaved forest, pitfall trap, 2001. VI.30–VII.3, X.-D. Yu & H.-Z. Zhou legg. (IZ-CAS); 1♂, Mt. Emei, 1983. VII.26, Z.- Y. Gou leg. ( CWNU); 1♀, Mt. Emei, Wan Nian Si [=Wan Nian Temple, 29.58ºN 103.38ºE], 1983. VII.26 [suspicious, for “26” written over “22”], “ III-12 ” ( CWNU). Guizhou: 1♀, Mt. Fanjing [27.94ºN 108.61º1], 1550 m, 2006. VIII.8, Z.-L. Zhang leg. ( CWNU). [Note: the CWNU specimens (1♂ 1♀) from Mt. Emei were identified by Prof. Zheng as “ paratype ” [in Chinese] on the stopper and tape of containing vials, but we did not find the label information of each present in the original material where there were no specimens collected on 1983. VII.26.]

Redescription. Body ( Fig. 17 A, B) shiny and dark brown; mouthparts and legs reddish brown. Body small in size, length [average]: ♂, 2.65 mm; ♀, 2.7 mm.

Male. Head ( Figs. 16 A; 17C) broadest at eyes. Disc pubescent, with setal punctures large but sparse, no microstriae. Clypeus with surface delicate and not punctate, protruding beyond anterior border of supra-antennal ridges, anterior margin truncate without modification. Epistomal suture fine and posteromedially directed. Supra-antennal ridges elevated. Vertex depressed anteriorly, without mid-longitudinal suture, where with setal puncture instead. Eyes convex, equal with temples in length, with fine facets; orbital sulcus fine. Temple slightly dilated laterally.

Neck constricted, and demarcated by occipital suture. Occipital suture integral and slightly curved. Mandible ( Fig. 18 A) short and incurved; bearing 3 teeth on inner edge: 2 large with 1 tiny in between.

Pronotum ( Figs. 16 A; 17C) wider than or equal with head, widest at anterior 1/3, with mid-longitudinal sulcus reduced, micro-striae absent, with a few large punctures lined or clustered; anterior margin broadly emarginate, anterior lateral angles less prominent, posterior angles rounded; lateral and posterior margins without crenulation, near lateral margin with shallow punctate depression. Scutellum with crest-shaped impression. Elytra ( Fig. 17 A) with posterior margin roundly truncate, elytral suture not overlapping.

Abdominal sternite VII ( Figs. 16 C; 18C) with posterior margin deep and semicircularly emarginate in middle, where modified by short semicircular membrane (not beyond posterior margin). Sternite VIII ( Figs. 16 D; 18D) posterior margin with broad, deep and sub-trapezoidal emargination.

Aedeagus ( Figs. 16 G–I; 18G–J) with median lobe ovoid; apical orifice fissure-like, reaching middle of ventral surface, edges of ventral fissure protruding into a pair of sharp triangular spines; internal sac with sclerite-like and membranous parts, not rolling. Paramere arm-like; basal arm with furrow; apical arm slightly explanate, furnished with setae at apex, with another seta near apex of ventral edge, by which a few pits lined.

Female. Similar to male ( Figs. 16 B; 17B, D; 18B). Abdominal sternite VII without modification, sternite VIII ( Figs. 16 E; 18E) gradually narrowed, with posterior margin nearly truncate and slightly protruding in middle. Spermatheca ( Figs. 16 F; 18F) constricted at middle, basal part inflated; apical part short, curved at apex.

Distribution. China (Guizhou, Sichuan).

Remarks. Similar to P. quedenfeldti Weise, 1879 , but P. quedenfeldti is with prominent posterior corners on the pronotum, and with two short spines on the posterior margin of sternite VIII.

Figures

FIGURE 16. Platystethus luae 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, aedeagus (ventral view); H, median lobe of aedeagus (lateral view); I, right paramere (in situ) of aedeagus (ventro-lateral view). Scales: A, B = 0.5 mm; F = 0.05 mm; rest, 0.2 mm.

FIGURE 17. Platystethus luae Zheng, 2000 II: A, habitus ♂; B, habitus ♀; C, head and pronotum ♂ (dorsal view); D, head and pronotum ♀ (dorsal view). Scales: 0.5 mm.

FIGURE 18. Platystethus luae 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 (lateral view); J, right paramere (in situ) of aedeagus (lateral view). Scales: F = 0.05 mm; rest, 0.2 mm.