Stenus lineatus 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 : 532-533

Stenus lineatus Tang, Liu & Dong , new species

(Figs 3, 22–27)

Material examined. Holotype: ♂, glued on a card with labels as follows: “ China: Sichuan Prov., Qingchengshan Mt., Baiyun Temple , 30°56'N, 103°28'E, alt . 1650 m, 29.VII.2012, Peng, Dai & Yin leg”. “Holotype / Stenus lineatus / Tang, Liu & Dong” [red handwritten label] (SHNU). Paratypes: 1♂ 1♀, same data as for the holotype. ( SHNU).

Description. Brachypterous; head blackish, rest parts dark brown. Antennae, maxillary palpi and legs yellowish brown except antennal club infuscate. Labrum reddish brown.

BL: 4.1–4.3 mm, FL: 2.0 mm.

HW: 0.77–0.84 mm, PL: 0.59–0.65 mm, PW: 0.58–0.65 mm, EL: 0.64–0.67 mm, EW: 0.71–0.79 mm, SL: 0.47–0.49 mm.

Head 1.06–1.08 times as wide as elytra; interocular area with two deep longitudinal furrows, median portion convex, reaching the level of inner eye margins; punctures round, slightly larger and sparser on median portion than those near inner margins of eyes, diameter of large punctures about as wide as apical cross section of antennal segment II; interstices smooth, mostly narrower than half the diameter of punctures except those along the midline of the median portion, which may be as wide as the diameter of punctures. Paraglossae oval.

Pronotum 0.91–1.03 times as long as wide; disk uneven, with distinct median longitudinal furrow which is about 1/2 the length of pronotum; punctures rugose and confluent, varied in size, slightly larger than those of head in average; interstices smooth, much narrower than half the diameter of punctures except for those in the middle of the median longitudinal furrow, which may be wider than the diameter of punctures.

Elytra 0.85–0.89 times as long as wide; disk relatively even; punctures moderately confluent, slightly larger than those of pronotum; interstices smooth, distinctly smaller than half the diameter of punctures.

Legs with tarsomeres IV strongly bilobed.

Abdomen cylindrical; paratergites very narrow with few puncures, present in segments III–VI, posterior margin of tergite VII without indistinct apical membranous fringe; interstices smooth, mostly wider than diameter of punctures except those on basal impressions of tergites III–V, which may be distinctly narrower than half the diameter of punctures.

Male. Sternites VI and VII with posteromedian porion flattened; sternite VIII ( Fig. 22 ) with distinct semicircular emargination at middle of posterior margin; sternite IX ( Fig. 23 ) with long apicolateral projections, posterior margin serrate. Aedeagus ( Figs. 24–25 ) with apical sclerotized area triangular with a sharp projection at apex, median lobe with two pairs of short subapical setae; expulsion clasps large, strongly sclerotized; parameres as long as the median lobe, flattened subapically, each with 23–26 setae on apico-internal margins.

Female. Sternite VIII ( Fig. 26 ) with posterior margin weakly pointed at middle; sclerotized spermatheca ( Fig. 27 ) with folded bends.

Distribution. China (Sichuan).

Remarks. The new species can be readily distinguished from other Chinese species of the cirrus group by presence of the paratergites in abdominal segments III–VI except S. huangganmontium Puthz, 2003 from Fujian and S. cirrus L. Benick, 1940 from Zhejiang, and it can be easily distinguished from the latter two species by larger body size.

Etymology. The specific name is derived from the presence of narrow paratergites in abdominal segments III–VI.

Figures

FIGURES 22–27. Stenus lineatus. 22 male sternite VIII 23 male sternite IX 24, 25 aedeagus 26 female sternite VIII 27 valvifers and spermatheca. Scale bars: 0.25 mm.