Stenus platydentatus, 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 platydentatus sp. nov.

( Figs 7 , 30–33 )

Type material. Hඈඅඈඍඒඉൾ: China: Yඎඇඇൺඇ: J, glued on a card with labels as follows: “Zhongdian Co., pass 28km ESE Zhongdian, devastated primary forest with young Abies, Larix, Belula, Rhodod , 27°43.9′N, 99°58.2′E, 3700–3750 m, 22.viii.2003, M.Schülke leg.”, “ Holotype / Stenus platydentatus / Shuai, Tang & Luo” [red handwritten label] ( MSBG). Pൺඋൺඍඒඉൾඌ: CHINA: Yඎඇඇൺඇ: 2 ♀♀, same label data as for the holotype ( MSBG); 1 ♀, Zhongdian Co., pass 28km ESE Zhongdian, 3700–3750 m, 27°43.9′N, 99°58.2′E, 22.viii.2003, A. Smetana leg. ( ASTJ); 1 ♀, Zhongdian Co., 36km ESE Zhongdian, 3500–3550 m, 27°40.9′N, 100°01.5′E,

23.viii.2003, A. Smetana leg. ( ASTJ); 1 ♀, Zhongdian Co., 36km ESE Zhongdian, overgrown rock hillside with old mixed forest, bamboo, dead wood, mushrooms, 3500–3550 m, 27°40.9′N, 100°01.5′E, 23.viii.2003, M. Schülke leg. ( MSBG); 1 ♀, Zhongdian Co., Bitai Hai Lake area, 29km ESE Zhongdian, 3540 m, 27°43.65′N, 99°58.97′E, creek valley, devastated mixed forest, litter, moss, dead wood, 1.vi.2005, M. Schülke leg. ( MSBG); 1 J 1 ♀, Zhongdian Co., 35km ESE Zhongdian, 3450 m, 27°41.00′N, 100°01.47′E, devastaded mixed forest near small creek, sifted from litter, moss, dead wood, 3.vi.2005, M. Schülke leg. ( SHNU).

Differential diagnosis. The new species resembles S. tenuidentatus sp. nov. and S. alpigenus sp. nov. from Yunnan but can be distinguished from them by stout aedeagal expulsion clasps ( Fig. 31 ) and slender spermatheca ( Fig. 33 ).

Description. Measurements. BL: 4.1–5.1 mm, FL: 2.2–2.4 mm. HW: 0.93–1.02 mm, PL: 0.71–0.84 mm, PW: 0.79–0.88 mm, EL: 0.85–0.93 mm, EW: 1.02–1.15 mm, SL: 0.62–0.76 mm. Head 0.89–0.96 times as wide as elytra; pronotum 0.90–0.97 times as long as wide; elytra 0.79–0.87 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; pronotum with impressions deeper, interstices partially reticulated, distinct in the actual middle of longitudinal furrow, actual middle of longitudinal furrow densely punctate, which is similar to remaining portions of pronotum; 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. 32 ) with distinct apicolateral projections, posterior margin serrate. Aedeagus ( Figs 30, 31 ) robust; apical sclerotized area of median lobe medium in length and pointed at tip; expulsion clasps stout, 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: 15–17 setae in distal and 5–7 setae in basal group.

Female. Sternite VIII prominent in middle of posterior margin; spermatheca ( Fig. 33 ) with basal porch slightly emarginated on apical margin, spermatheca duct strongly sclerotized and coiled at the first bend, capsule small.

Etymology. The species name is derived from the broad 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 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.