Stenus brevilineatus 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 : 537-538

Stenus brevilineatus Tang, Liu & Dong , new species

(Figs 7, 44–49)

Material examined. Holotype: ♂, glued on a card with labels as follows: “ CHINA: W - Sichuan, Ya’an Pref, Tianquan Co, Jiajin Shan , valley above Labahe, N.R. Station, 57 km,W-Ya’an, 36.06.63N, 102.25.18E, light forest, 1800m, 12.VII.1999, leg. A.Pütz, Sammlung, Andreas Pütz, Eisenhuttenstadt . coll. Pütz ”. “ Holotype / Stenus brevilineatus / Tang, Liu & Dong ” [red handwritten label] (cPüt) . Paratypes: 1♀, same data as for the holotype. (cPüt).

Description. Brachypterous; body blackish with pronotum and elytra inditinctly lighter. Antennae, maxillary palpi and legs yellowish brown except antennal club infuscate. Labrum reddish brown.

BL: 4.2–4.6 mm, FL: 1.9–2.3 mm.

HW: 0.78–0.90 mm, PL: 0.59–0.70 mm, PW: 0.62–0.72 mm, EL: 0.78–0.92 mm, EW: 0.82–1.01 mm, SL: 0.57–0.69 mm.

Head 0.90–0.95 times as wide as elytra; interocular area with two deep longitudinal furrows, median portion moderately convex, extending beneath the level of inner eye margins; punctures rather confluet, similar in size, diameter of punctures about as wide as apical cross section of antennal segment II; interstices smooth, distinctly narrower than half the diameter of punctures. Paraglossae oval.

Pronotum 0.95–9.97 times as long as wide; disk uneven, with distinct median longitudinal furrow which is about 2/3 the length of pronotum; punctures very confluent, varied in size, mostly similar to those of head; interstices ridge like and indistinctly sculptured, much narrower than half the diameter of punctures except for those in the middle of the median longitudinal furrow, which may be twice as wide as the diameter of punctures.

Elytra 0.93–0.94 times as long as wide; disk relatively even; punctures strongly confluent, slightly larger than those of pronotum; interstices similar to those of pronotum.

Legs with tarsomeres IV strongly bilobed.

Abdomen cylindrical; paratergites very narrow and almost impunctate, present only in segments III and IV, sutures between tergites and sternites present in rest segments; punctation elliptic?thick on tergite III and basal portion of tergites IV and V, gradually becoming very small and sparser posteriad; interstices smooth, as wide as to far more wider than diameter of punctures except those on tergite III and basal portion of tergites IV and V, which may be distinctly narrower than half the diameter of punctures.

Male. Sternite VIII ( Fig. 44 ) with distinct emargination at middle of posterior margin; sternite IX ( Fig. 45 ) with distinct apicolateral projections, posterior margin nearly straight. Aedeagus ( Figs. 46, 47 ) with apical sclerotized area triangular; expulsion clasps large, strongly sclerotized; parameres longer than the median lobe, each with 21–22 setae on apico-internal margins.

Female. Sternite VIII ( Fig. 48 ) entire; sclerotized spermatheca ( Fig. 49 ) with long folded bends.

Distribution. China (Sichuan).

Remarks. The new species is similar to S. lineatus sp.n., but can be easily distinguished from the latter species by more confluent punctation of forebody, longer elytra and the absence of paratergites on abdominal segments V and VI.

Etymology. The specific name is derived from the presence of narrow paratergites in first two visible abdominal segments.

Figures

FIGURES 44–49. Stenus brevilineatus. 44 male sternite VIII 45 male sternite IX 46, 47 aedeagus 48 female sternite VIII 49 valvifers and spermatheca. Scale bars: 0.25 mm.