Stenus paratrigonuroides, 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 : 625

Stenus paratrigonuroides sp. nov.

( Figs 9 , 38–41 )

Type material. Hඈඅඈඍඒඉൾ: CHINA: Yඎඇඇൺඇ: J, glued on a card with labels as follows: “NW Deqen, Baima Xue Shan, 28.20°N, 99.03°E, 4000–4300 m, conif, Rhodod, 16–20.vi.2016, Reuter leg.”, “ Holotype / Stenus paratrigonuroides / Shuai, Tang & Luo” [red handwritten label] ( VPSG). Pൺඋൺඍඒඉൾඌ: CHINA: Yඎඇඇൺඇ: 2 JJ 3 ♀♀, same label data as for the holotype ( VPSG, SHNU); 1 ♀, Deqin Co., Baima Shan, E-side, pass 12km SE Deqin, 28°23.86′N, 99°59.04′E, 4085 m, small creek valley Rhododendron, Salix , leaf litter, moss, dead wood sifted, 10.vi.2005, M. Schülke leg. ( MSBG); 1 ♀, Deqin Co., Baima Shan, pass 15km SE Deqin, 28°22.68′N, 99°00.57′E, 4330 m, meadows, Azalea, Juniperus , leaf litter, grass, moss, sifted, 12.vi.2005, M. Schülke leg. ( MSBG); 1 ♀, Deqin Co., Baima Shan, pass 15km SE Deqin, 28°22.68′N, 99°00.57′E, 4330 m, 12.vi.2005, A. Smetana leg. ( ASTJ).

Differential diagnosis. The new species resembles S. trigonuroides from West China and S. aureolus from the Far East but can be distinguished from both by longer apical sclerotized area of the aedeagal median lobe ( Fig. 39 ) and short hind wings. It also differs from S. aureolus ( Fig. 14 ) in the coiled spermatheca duct ( Fig. 41 ). See also Differential diagnoses of these species.

Description. Measurements. BL: 3.8–4.5 mm, FL: 2.0– 2.3 mm. HW: 0.81–0.87 mm, PL: 0.61–0.68 mm, PW: 0.65–0.73 mm, EL: 0.79–0.86 mm, EW: 0.85–0.93 mm, SL: 0.66–0.76 mm. Head 0.91–0.98 times as wide as elytra; pronotum 0.91–0.99 times as long as wide; elytra 0.90–0.97 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, interstice in middle of midline of median convex portion slightly larger than diameter of punctures; hind wings slightly longer, about half the length of elytra; abdominal tergite VII with apical membranous fringe; abdominal tergites III–VI 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. 40 ) with distinct apicolateral projections, posterior margin serrate. Aedeagus ( Figs 38, 39 ) slender; apical sclerotized area of median lobe long and pointed at tip; expulsion clasps slender, 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: 14–18 setae in distal and 6 setae in basal group.

Female. Sternite VIII prominent in middle of posterior margin; spermatheca ( Fig. 41 ) sclerotized with basal porch bilobed, spermatheca duct coiled at first bend, capsule small.

Etymology. The species name refers to the striking similarity of this species with S. trigonuroides ; the suffix - oides (same for all genders) means ‘resembling’.

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.

Figs 11–18. Sexual characters. 11–14 – Stenus aureolus Fauvel, 1875; 15–18 – S. trigonuroides Zheng, 1993. 11, 12, 15, 16 – aedeagus; 13, 17 – male sternite IX; 14, 18 – spermatheca. Scale bars = 0.25 mm.