Ocychinus angustiarum, Smetana, Aleš, 2006

Smetana, Aleš, 2006, Contributions to the knowledge of the “ Staphylinus­complex ” (Coleoptera: Staphylinidae: Staphylinini) of China. Part 14. The genus Ocychinus Smetana 2003. Section 2, Zootaxa 1317, pp. 35-40 : 37-38

Ocychinus angustiarum spec. nov.

( Figs. 1–5 )

Type material. Holotype (male): CHINA: Yunnan: “ China, N Yunnan Deqen—SE env., 4100–4600 m 28°25' / 99°00' 27– 30.6.92 L. + R. Businský lgt.” (ASC). Allotype (female): CHINA: Yunnan: same data as holotype (ASC). Paratypes: CHINA: Yunnan: same data as holotype, 8♂♂, 15ΨΨ (ASC, MDC).

Description. Black, forebody moderately shiny; pubescence of dorsal side of body black; maxillary and labial palpi piceous with apices of segments slightly paler; antennae black, legs black with front tarsi somewhat paler. Head of rounded quadrangular shape, with widely rounded posterior angles, wider than long (ratio 1.35), eyes small, slightly convex, tempora considerably longer than eyes seen from above (ratio 2.50), posterolateral portions of head with rather fine, very dense punctation, punctation becoming gradually markedly sparser towards midline and frons, impunctate midline reduced to inconspicuous remnant in front of posterior margin of head; interspaces between puntures with very fine microsculpture. Antenna long; segment 3 markedly longer than segment 2 (ratio 1.37), segments 4–9 longer than wide, becoming gradually shorter, segment 10 about as long as wide, last segment shorter than two preceding segments combined. Pronotum vaguely longer than wide (ratio 1.1), almost parallelsided, narrow marginal groove disappearing downwards at about anterior fourth of pronotal length; disc of pronotum with complete, narrow impunctate midline; punctation and pubescence similar to that on head but finer and denser, gradually becoming somewhat sparser anteromediad, interspaces between punctures with microsculpture similar to that on head. Scutellum finely and densely punctate and pubescent on posterior half, surface with almost obsolete, rudimentary microsculpture. Elytra short, slightly dilated posteriad, at suture considerably (ratio 0.65), at sides markedly (ratio 0.77) shorter than pronotum at midline; punctation very fine and very dense, finely asperate, interspaces between punctures with fine, dense, granulose microsculpture, elytra therefore appearing dull. Wings each folded under elytron, but likely nonfunctional. Abdomen with tergite 7 (fifth visible) without pale apical seam of palisade setae; tergite 2 (in front of first visible tergite) entirely, densely punctate and pubescent; all tergites very finely and densely punctate, punctation finer than that on elytra, almost evenly covering each tergite, but in general gradually becoming vaguely sparser toward apex of abdomen; interspaces between punctures with extremely fine, submeshed microsculpture.

Male. Sternite 8 with moderately wide and deep, obtusely triangular medioapical emargination. Male genital segment with sternite 9 rather deeply, obtusely triangularly emarginate apically and with one long, strong seta at each lateral margin before apex ( Fig. 1 ). Tergite 10 markedly narrowed toward narrowly arcuate apex, densely setose at apex, otherwise moderately densely setose. Aedoeagus as in Figs. 2–4 ; median lobe with parallel­sided middle portion, narrowed into asymmetrical apical portion with acute apex; paramere situated on median lobe asymmetrically, symmetrical apical portion with narrowly arcuate apex distinctly not reaching apex of median lobe; underside of paramere with a few inconspicuous, not pigmented sensory peg setae, several minute, variably long setae situated along both lateral margins and at apex of apical portion of paramere ( Fig. 4 ).

Female. Tergite 10 of genital segment large, markedly narrowed toward acute apex, with numerous setae at apex, otherwise moderately densely setose ( Fig. 5 ).

Length 20.0–22.0 mm (moderately extended abdomen).

Geographical distribution. Ocychinus angustiarum is at present known from the type locality in Baima Shan in northern Yunnan (see Comments).

Bionomics. The specimens were taken from pitfall traps set apparently in the subalpine/alpine zone of the pass, but no details about the actual habitat are available.

Recognition and comments. Ocychinus angustiarum is at present the largest species of the genus. It is most similar to O. nigrita Smetana 2003 , but differs from it abundantly, in addition to the differences in the shape of the aedoeagus, by the markedly longer and stronger antenna, by the presence of microsculpture on the interspaces between punctures on the head and pronotum, and by the presence of the two long lateral setae on sternite 9 of the male genital segment.

The type locality of this species is the pass in the Baima Shan about 15km SE Deqin in northern Yunnan.

Etymology. The specific epithet is the genitive form of the Latin noun angustiae, ­ arum, (mountain pass). It refers to the occurrence of this species in the pass SE Deqin.

Figures

FIGURES 1 – 9. Details of Ocychinus angustiarum (1 – 5) and O. kalabi (6 – 9). 1, 6 — sternite 9 of male genital segment; 2, 8 — aedoeagus, ventral view; 3 — apical portion of aedoeagus, lateral view; 4, 9 — underside of apical portion of paramere; 5 — tergite 10 of female genital segment; 7 — tergite 10 of male genital segment.