Stenus aduncus, 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

Stenus aduncus sp. nov.

( Figs 6 , 27–29 )

Type material. Hඈඅඈඍඒඉൾ: CHINA: SංർΗඎൺඇ: J, glued on a card with labels as follows: “Jiajinshan, Jintang, 3550–3650 m, 18km E primary coniferous forest, 11–24.vi.2004, R. Fabbri leg.”, “ Holotype / Stenus aduncus / Shuai, Tang & Luo” [red handwritten label] ( MSBG).

Differential diagnosis. The new species resembles S. platydentatus sp. nov., S. tenuidentatus sp. nov. and S. alpigenus sp. nov. from Yunnan in general habitus but can be distinguished from all of them by apical sclerotized area of the median lobe shorter and expulsion clasps ( Fig. 28 ) less protruded inwards medially.

Description. Measurements. BL: 4.2 mm, FL: 2.2 mm. HW: 0.84 mm, PL: 0.65 mm, PW: 0.70 mm, EL: 0.70 mm, EW: 0.87 mm, SL: 0.56 mm. Head 0.96 times as wide as elytra; pronotum 0.92 times as long as wide; elytra 0.81 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, about 1–1.5 times as wide as diameter of punctures along midline of median convex portion; pronotum with impressions deeper, interstices almost smooth, rarely with traces of microsculpture, actual middle of longitudinal furrow densely punctate, which is similar to remaining portions of pronotum; emargination of hind tarsomeres IV deeper.

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. 29 ) with distinct apicolateral projections, posterior margin serrate. Aedeagus ( Figs 27, 28 ) slender; apical sclerotized area of median lobe relatively short with pointed tip; expulsion clasps strongly sclerotized, weakly protruded inwards medially; copulatory tube broad; parameres much longer than median lobe, swollen in apical parts, each with two groups of setae on apico-internal margins: 14–15 setae in distal and 6–7 setae in basal group.

Female. Unknown.

Etymology. The specific name is derived from the hook -shaped expulsion clasps of aedeagus; adjective.

Distribution. China (Sichuan).

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 27–33. Sexual characters. 27–29 – Stenus aduncus sp. nov.; 30–33 – S. platydentatus sp. nov. 27, 28, 30, 31 – aedeagus; 29, 32 – male sternite IX; 33 – spermatheca. Scale bars = 0.25 mm.