Stenus jiudingshanus Tang, Liu & Dong, 2018

Tang, Liang, Liu, Sheng-Nan & Dong, Xin-Yu, 2018, Seven new species of the Stenus cirrus group (Coleoptera, Staphylinidae) from Sichuan, Southwest China, Zootaxa 4425 (3), pp. 527-540 : 534-536

Stenus jiudingshanus Tang, Liu & Dong , new species

(Figs 5, 34–39)

Material examined. Holotype: ♂, glued on a card with labels as follows: “ Ganlong Chi (2500–2750 m). Mt. Jiuding Shan (Chaping Shan Mts). Mao Xian, Sichuan prov. SE China. 23.IX.1996. S. Nomura. coll. Watanabe ” . “Holotype / Stenus jiudingshanus / Tang, Liu & Dong” [red handwritten label] (cWat). Paratypes: 1♂ 2♀♀, same data as for the holotype. (cWat, SHNU) .

Description. Brachypterous; Head black, rest parts reddish brown with elytra slightly lighter. Antennae, maxillary palpi yellowish brown except antennal club infuscate, legs reddish yellow.

BL: 3.2–3.3 mm, FL: 1.5 mm.

HW: 0.68–0.73 mm, PL: 0.50–0.53 mm, PW: 0.49–0.53 mm, EL: 0.52–0.54 mm, EW: 0.58–0.64 mm, SL: 0.39–0.42 mm.

Head 1.11–1.16 times as wide as elytra; interocular area with two deep longitudinal furrows, median portion convex, reach the level of inner eye margins; punctures roundand almost uniformed, diameter of punctures slightly wider than apical cross section of antennal segment II; interstices smooth, mostly narrower than half the diameter of punctures except few along the midline of the posterior median portion, which may be wider than the diameter of punctures. Paraglossae oval.

Pronotum 0.98–1.02 times as long as wide; disk uneven, with distinct median longitudinal furrow; two shallow impressions in anterior half, two shallow impressions in about middle and two shallow impressions in posterior half; punctures strongly confluent, similar size to those of head; interstices smooth, much narrower than half the diameter of punctures except in median furrow, which may be twice as wide as the diameter of punctures.

Elytra 0.85–0.92 times as long as wide; disk uneven with distinct longitudinal humeral impression, distinct postero-lateral impression and distinct long sutural impression, suture convex; punctures confluent, of similar size to those of pronotum; interstices smooth, much narrower than half the diameter of punctures.

Legs with tarsomeres IV strongly bilobed.

Abdomen cylindrical; paratergites very narrow with few punctures, present only in segment III, tergites and sternites totally fused in segments IV–VI, posterior margin of tergite VII with indistinct apical membranous fringe; punctation round, clear and relatively dense; interstices smooth, narrower than half the diameter of punctures to narrower than diameter of punctures.

Male. Sternite VIII ( Fig. 34 ) with shallow emargination at middle of posterior margin; sternite IX ( Fig. 35 ) with long apicolateral projections. Aedeagus ( Figs. 36–37 ) with median lobe robust, apical sclerotized area triangular and roundly projected at apex; expulsion clasps large; parameres longer than median lobe, swollen at apical parts, each with 8–10 setae on apico-internal margins.

Female. Sternite VIII entire; spermatheca ( Fig. 38 ) strongly sclerotized, spermathecal ( Fig. 39 ) duct consisting of basal duct and complicatedly folded spermatheca duct.

Distribution. China (Sichuan).

Remarks. The species can be readily distinguished from other species of the cirrus group by small body size and the coloration.

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

Figures

FIGURES 34–39. Stenus jiudingshanus. 34 male sternite VIII 35 male sternite IX 36, 37 aedeagus 38 female sternite VIII 39 valvifers and spermatheca. Scale bars: 0.25 mm.