Stenus dongbaishanus Tang, Liu & Zhao, 2017

Zhao, Tie-Xiong, 2017, A study on the genus Stenus Latreille from Zhuji City of Zhejiang, East China (Coleoptera, Staphylinidae), Zootaxa 4323 (1), pp. 25-38 : 27-28

Stenus dongbaishanus Tang, Liu & Zhao , new species

( Figs. 2 , 8–12 )

Type material. Holotype. China: Zhejiang: Zhuji : ♂, glued on a card with labels as follows: “ China : Zhejiang Province, Zhuji City, Dongbaishan, Tanyueling, mixed forest leaf litter, sifted, alt. 850m, 30.31. VIII.2014, Tie-Xiong Zhao leg.” “ Holotype / Stenus dongbaishanus / Tang, Zhao & Luo” [red handwritten label] ( SHNU) . Paratypes. 14♂♂ 19♀♀, same data as for the holotype ( SHNU, cPut) ; 7♂♂5♀♀, Dongbaishan, mixed forest, leaf litter, sifted, alt. 900m, 21.VII.2014, Tie-Xiong Zhao leg (SHNU).

Description. Brachypterous. Head black with clypeus and labrum reddish brown, pronotum and elytra reddish brown, abdomen brownish. Antennae reddish brown, club infuscate, maxillary palpi and legs yellowish brown.

BL: 2.7–3.0mm, FL: 1.4–1.5 mm. HW: 0.67–0.73 mm, PL: 0.50–0.53 mm, PW: 0.50–0.54 mm, EL: 0.50–0.54 mm, EW: 0.52–0.64 mm, SL: 0.37–0.39 mm.

Head 1.14–1.38 times as wide as elytra; interocular area with two deep longitudinal furrows, median portion convex, extending a little beyond the level of inner eye margins; punctures round, mostly well delimited, slightly confluent on median portion, almost same in size, diameter of punctures slightly narrower than apical cross section of antennal segment II; interstices shallowly reticulated, distinctly narrower than half the diameter of punctures except those along the midline of the posterior half of the median portion, which may be as wide as triple the diameter of punctures. Paraglossa oval.

Pronotum 0.95–1.00 times as long as wide; disk slightly uneven, with broad median longitudinal furrow; punctures confluent, different in size, a little larger to smaller than those of head; interstices reticulated and rugaelike, mostly narrower than half the diameter of punctures except those at the actual middle of longitudinal furrow, which may be as wide as twice the diameter of punctures.

Elytra 0.84–1.01 times as long as wide; disk relatively even, with humeral impression more or less distinct; punctures and interstices similar to those of pronotum except the reticulation indistinct.

Legs with tarsomeres IV deeply bilobed.

Abdomen cylindrical; segment III with paratergites very narrow and punctate, directed ventrad, segments IV– VI with tergites and sternites entirely fused, tergite VII without apical membranous fringe; punctures round to elliptic, becoming slightly smaller posteriad; interstices reticulated, narrower than half the diameter of punctures on tergite III, narrower than diameter of punctures on tergite IV and V.

Male. Sternite VI and VII with posteriomedian portion flattened, sternite VIII ( Fig. 9 ) with semicircle emargination at middle of posterior margin;sternite IX ( Fig. 8 ) with long apicolateral projections, posterior margin serrate and almost straight. Aedeagus ( Figs. 10, 11 ) stout; apical sclerotized area of median lobe very wide and very short with a point apical projection at middle; expulsion clasps large, strongly sclerotized; parameres much longer than median lobe, tapering apicad at apical third, each with 5–6 subapical setae and 3–4 basal setae on apico-internal margins.

Female. Sternite VIII inconspicuously prominent at middle of posterior margin; spermatheca ( Fig. 12 ) with basal porch strongly sclerotized, spermathecal duct sclerotized and bent thrice.

Distribution. China (Zhejiang).

Remarks. The species belongs to Stenus cephalotes group and resembles S. micuba Hromádka, 1982 from Jiangsu, S. breviculus Tang, Li & Puthz, 2010 from Zhejiang and S. pseudomicuba Tang, Puthz & Yue, 2016 from Zhejiang, but can be distinguished from them by the larger body size, from the latter two species also by the presence of the paratergites on abdominal segment III.

Etymology. The specific name is derived from the type locality of this species.

Figures

FIGURES 1 – 2. Habitus 1 Stenus dongbaishanus 2 S. zhejiangensis. Scales = 1 mm.

FIGURES 8 – 11. Stenus zhejiangensis 8 male sternite IX 9 male sternite VIII 10, 11 aedeagus. Scale bars = 0.25 mm.

FIGURES 12 – 15. 12 Stenus alumoenus 13, 14 S. gastralis 15 S. kuatunensis 1 2, 13 15 aedeagus 14 apical portion of aedeagus in lateral view. Scale bars = 0.25 mm.