Stenus fengyangshanus Tang & Jiang, 2018

Tang, Liang & Jiang, Zhuo-Heng, 2018, Three new species of the Stenus cephalotes group fom Zhejiang, East China (Coleoptera, Staphylinidae), Zootaxa 4472 (2), pp. 298-306 : 302-305

Stenus fengyangshanus Tang & Jiang , sp. n.

( Figs. 5, 6 , 19–24 )

Type material. Holotype. China: Zhejiang: ♂, glued on a card with labels as follows: “China: Zhejiang Province, Longquan City, Mt. Fengyang, Huangmaojian , 27°53'24''N, 119°10'33''E, alt. 1400m, mixed forest leaf litter, sifted, 23.V.2018, Tang, Cheng & Shuai leg.” “Holotype / Stenus fengyangshanus / Tang & Jiang” [red handwritten label] ( SHNU) . Paratypes. 2♂♂ 9♀♀, same data as for the holotype ( SHNU, cPut) ; 11♂♂ 9♀♀, same locality, but 27°54'34''N, 119°10'20''E, alt. 1170–1300m, 7.X.2013, Feng, Peng, Yu & Yin leg. ( SHNU)

Description. Brachypterous. Head black with clypeus and labrum blackish brown, rest body parts dark brown with elytra slightly lighter. Antennae yellowish brown, club infuscate, maxillary palpi and legs yellowish brown.

BL: 2.8–3.2 mm, FL: 1.5–1.7 mm. HW: 0.71–0.81 mm, PL: 0.54–0.58 mm, PW: 0.52–0.55 mm, EL: 0.50–0.57 mm, EW: 0.58–0.66 mm, SL: 0.38–0.43 mm.

Head 1.22–1.26 times as wide as elytra; interocular area with two deep longitudinal furrows, median portion convex, reaching the level of inner eye margins; punctures round, mostly well delimited, slightly confluent and larger on median portion, diameter of most punctures slightly narrower than apical cross section of antennal segment II; interstices patially with indistinct reticulation, 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 diameter of punctures. Paraglossa oval.

Pronotum 1.01–1.05 times as long as wide; disk slightly uneven, with shallow median longitudinal furrow; punctures more or less confluent, different in size, a little larger to smaller than those of head; interstices smooth and rugae-like, mostly narrower than half the diameter of punctures except those at the actual middle of longitudinal furrow, which may be 1.5 time as wide as diameter of punctures.

Elytra 0.85–0.90 times as long as wide; disk relatively uneven, with humeral impression, sutural impression and posterolateral impression more or less distinct; punctures and interstices similar to those of pronotum except the punctation a little larger in size.

Legs with tarsomeres IV deeply bilobed.

Abdomen cylindrical; segment III with narrow paratergites only on basal half, segments IV–VI without paratergites though tergites and sternites distinctly separated by sutures, tergite VII with indistinct apical membranous fringe; punctures round to elliptic, becoming slightly smaller posteriad; interstices mostly narrower than half the diameter of punctures on tergite III–VI, reticulation througout, becoming more distinct posteriad.

Male. Sternite VII with posteriomedian portion flattened, posterior margin of flattened portion slightly emarginated; sternite VIII ( Fig. 19 ) roundly emarginated at middle of posterior margin; sternite IX ( Fig. 20 ) with long apicolateral projections, posterior margin serrate and emarginated. Aedeagus ( Figs. 21, 22 ) slender; apical sclerotized area subtriangular; expulsion clasps large, strongly sclerotized and and conjointed; parameres much longer than median lobe, slihgtly swollen at apical third, each with 12–14 setae on apico-internal margins.

Female. Sternite VIII ( Fig. 23 ) indistinctly prominent at middle of posterior margin; spermatheca ( Fig. 24 ) with basal porch sclerotized, spermathecal duct with complicated bends and capsule large.

Distribution. China (Zhejiang).

Remarks. The species can be easily distinguished from other members of the group by following characters: pronotum, elytra and abdomen uniformly dark brown, interstices of pronotum smooth, abdominal punctation dense, abdominal segments without paratergites, each segment with tergite and sternite separated by sutures.

Etymology. The specific name is derived from “Fengyangshan”, the type locality of this species.

Figures

FIGURES 5, 6. Stenus fengyangshanus. 5 habitus in dorsal view 6 habitus in ventral view. Scale bars: 1mm.

FIGURES 19–24. Stenus fengyangshanus. 19 male sternite VIII 20 male sternite IX 19, 21, 22 aedeagus 23 female sternite VIII 24 valvifers and spermatheca. Scale bars: 0.25mm.