Stenus tenuidentatus, Shuai & Tang & Luo, 2020

Shuai, Qi, Tang, Liang & Luo, Yong-Ting, 2020, A review of the Stenus aureolus group of China (Coleoptera: Staphylinidae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 60 (2), pp. 615-627 : 623-625

Stenus tenuidentatus sp. nov.

( Figs 8 , 34–37 )

Type material. Hඈඅඈඍඒඉൾ: CHINA: Yඎඇඇൺඇ: J, glued on a card with labels as follows: “Xue Shan nr. Zhongdian, 3800 m, 27°49’N, 99°34’E, 26.iv.1996, A.Smetana, J. Farkač & P.Kabátek leg.”, “ Holotype / Stenus tenuidentatus / Shuai,Tang & Luo” [red handwritten label] ( ASTJ).Pൺඋൺ- ඍඒඉൾඌ: CHINA: Yඎඇඇൺඇ: 1J 7♀♀, same label data as for the holotype ( ASTJ, SHNU); 1 J, Zhongdian Co., 10 km SW Zhongdian, Xue Shan, 3800 m, 27°46.5′N, 99°36.5′E, 20.viii.2003, A. Smetana leg. ( SHNU).

Differential diagnosis. The new species resembles S. platydentatus sp. nov. and S. alpigenus sp. nov. from Yunnan but can be distinguished from them by slender aedeagal expulsion clasps ( Fig. 35 ) and the spermatheca duct stout, strongly coiled at first bend ( Fig. 37 ).

Description. Measurements. BL: 4.1–4.8 mm, FL: 1.9–2.4 mm. HW: 0.82–0.93 mm, PL: 0.65–0.71 mm, PW: 0.71–0.79 mm, EL: 0.71–0.81 mm, EW: 0.88–0.98 mm, SL: 0.56–0.63 mm. Head 0.89–0.97 times as wide as elytra; pronotum 0.86–0.96 times as long as wide; elytra 0.77–0.84 times as long as wide.

Morphology. The species is similar to Stenus mendaensis sp. nov. in most aspects except for the following characters: head with interstices smooth, interstices along midline of median convex portion very variable in different individuals, varied from distinctly smaller than half the diameter of punctures to distinctly larger than diameter of punctures; hind wings minute, nearly invisible; abdominal tergites III–VII with interstices smooth.

Male. Mesotibiae and metatibiae each with tooth on inner side of apex; sternite VIII with triangular emargination in middle of posterior margin;sternite IX ( Fig. 36 ) with distinct apicolateral projections, posterior margin serrate.Aedeagus ( Figs 34, 35 ) stout; apical sclerotized area of median lobe medium in length and pointed at tip; expulsion clasps slen- der, strongly sclerotized; copulatory tube long and broad; parameres much longer than median lobe, swollen in apical parts, each with two groups of setae on apico-internal margins: 14 setae in distal and 6–8 setae in basal group.

Female. Sternite VIII prominent in middle of posterior margin; spermatheca ( Fig. 37 ) strongly sclerotized, basal porch distinctly emarginated on apical margin, spermatheca duct stout, strongly coiled at first bend, capsule small.

Etymology. The specific name is derived from the slender expulsion clasps of aedeagus; adjective.

Distribution. China (Yunnan).

Figures

Figs 6–10. Habitus. 6 – Stenus aduncus sp. nov.; 7 – S. platydentatus sp. nov.; 8 – S. tenuidentatus sp. nov.; 9 – S. paratrigonuroides sp. nov.; 10 – S. alpigenus sp. nov. Scale bars = 1 mm.

Figs 34–41. Sexual characters. 34–37 – Stenus tenuidentatus sp. nov.; 38–41 – S. paratrigonuroides sp. nov. 34, 35, 38, 39 – aedeagus; 36, 40 – male sternite IX; 37, 41 – spermatheca. Scale bars = 0.25 mm.