Stenus (Hypostenus) cuneatus Zhao, Cai & Zhou

Zhao, Cai-Yun, Cai, Wan-Zhi & Zhou, Hong-Zhang, 2008, Two new Stenus (Hypostenus) species from China (Coleoptera, Staphylinidae, Steninae), Zootaxa 1725, pp. 48-52 : 50-51

Stenus (Hypostenus) cuneatus Zhao, Cai & Zhou , sp. n.

( Figs. 4–8 )

Type material. Holotype: CHINA: Hubei Prov.: male, Shennongjia, Shennongding (110°03'– 110°34'E, 31°21'– 31°36'N), 26 July 1998, 2800–2900 m, He Jun-jian collected. Paratypes: CHINA: Hubei Prov.: 4 females, same data as holotype.

Description. Body length: 3.0 mm.

Body black, pronotum and elytra reddish brown; antennae reddish brown with two apical segments black; maxillary palpi yellowish brown; clypeus and labrum dark brown and covered with white pubescence, anterior margin of labrum yellow; legs reddish brown.

Head distinctly wider than elytra (1.07:1), average distance between eyes 0.35 mm. Interocular area with a pair of parallel deep furrows, median part between furrows convex and almost reach inner margin of eyes, broader than each lateral portion; vertex without median impuncate area; punctures on head smaller than basal cross section of antennal segment III, interstices with microsculpture and larger than puncture diameter. Antenna short, not reaching middle of pronotum when reflexed, three apical segments longer than wide. Paraglossae oval.

Pronotum wider than long (1.12:1), widest in middle, strongly constricted anteriad and posteriad; surface of pronotum uneven, with distinct (weaker anteriad and posteriad) punctured median longitudinal furrow 2/3 of length of pronotum; with transverse depression near anterior margin of pronotum; punctures on pronotum coarse, larger than basal cross section of antennal segment III, interstices with microsculpture and smaller than puncture diameter. Elytra, measured along suture, distinctly shorter than pronotum (0.80:1), wider than long (1.22:1), sides distinctly inflated, widest at posterior 1/4, slightly constricted posteriad. Each elytron with shallow emargination in outer part of posterior margin, and hind margin of both elytra combined form shallow emargination. Surface of elytra flat, with indistinct humeral depression and shallow depression along suture gradually becoming shallower and narrower posteriad. Punctures on elytra irregular, smaller than basal cross section of antennal segment III, interstices with microsculpture and larger than puncture diameter. Hind wings reduced.

Legs robust, metatarsi 1st segment slightly shorter than 5th, 4th segment bilobed.

Abdomen robust, only 3rd abdominal segment with narrow paratergite; tergites and sternites of 4th–6th segments completely fused and only with slight trace of suture at base; 3rd–6th tergites with transverse basal impression; punctures on tergites coarse, on 3rd tergite as large as basal cross section of antennal segment III, interstices smaller than puncture diameter; punctures on subsequent tergites gradually smaller and sparser posteriad; puncture diameter on 7th tergite smaller than inner eye-facet, interstices larger than puncture diameter.

Male: 8th abdominal sternite with very shallow median emargination ( Fig. 6 ), apex of 9th sternite with two strong teeth and without denticles on outside of teeth ( Fig. 5 ). Aedeagus ( Fig. 4 ): apex of median lobe slightly blunt, with strong median hook ( Fig. 7 ); parameres about as long as median lobe, with sparse long hairs.

Female: All sternites with nearly round posterior margin, spermatheca as in Fig. 8 .

Etymology. The species epithet is derived from Latin words cuneatus (cuneal).

Remarks. This new species belongs to micuba group (for definition of this group see Naomi 1990). It differs from S. hlavaci Puthz, 2003 in having shorter antennae. It is more similar to S. micuba Hromádka, 1982 and S. ignobilis Puthz, 2003 in appearance, but can be distinguished from them by shorter parameres.

Figures

FIGURES 1 – 8. Details of Stenus (H.) trifurcatus sp. n. (1 - 3) and S. (H.) cuneatus sp. n. (4 - 8). 1, 4 — aedeagus; 2, 5 — male sternite IX; 3, 6 — male sternite VIII; 7 — hooks of internal sac; 8 — spermatheca. Scale bars: 0.1 mm.