Dianous bimaculatus, Cameron, 1927

Tang, Liang & Huang, Meng-Chi, 2018, Notes on the Dianous bimaculatus complex with description of a new species from China (Coleoptera, Staphylinidae), Zootaxa 4527 (4), pp. 560-568 : 568

Key to species of the Dianous bimaculatus complex from China

1 Head narrow, HW/EW: 0.76–0.83. BL: 6.1–6.7 mm. Habitus: Fig. 6 ; male characters: Figs. 11–13 in Puthz, 1995. China (Yunnan), Vietnam, Thailand.................................................................... D. strabo Puthz

- Head wide, HW/EW: 0.91–1.08.......................................................................... 2

2 Legs with femora bicolor. BL: 4.6–4.9 mm. Habitus: Fig. 5 ; sexual characters: Figs. 34–40 . China (Yunnan), Myanmar, Thailand, Vietnam..................................................................... D. siamensis Rougemont

- Legs with femora unicolor.............................................................................. 3

3 Elytral spots large, reaching lateral sides of elytra............................................................. 4

- Elytral spots small, far away from lateral sides of elytra....................................................... 5

4 Elytral spots smaller with diameter shorter than antennal segment IV, punctation of forebody denser and more or less confluent. BL: 5.5–6.7 mm (cited from Puthz, 1980). Habitus: Fig. 1 ; male characters: Figs. 7, 8. China (Yunnan), India, Nepal, Thailand, Bhutan...................................................................... D. bimaculatus Cameron

- Elytral spots larger with diameter as long as antennal segment IV, punctation of forebody sparser and well delimited. BL: 6.2– 6.8 mm. Habitus: Fig. 3 ; sexual characters: Figs. 17–24 . China (Hubei)..................... D. hubeiensis Tang & Huang

5 Smaller species, FL: 3.2–3.4 mm, elytral spots longer than wide. BL: 6.2–6.6 mm. Habitus: Fig. 4 ; sexual characters: Figs. 25– 33 . China (Hainan, Yunnan)............................................................. D. hainanensis Puthz

- Larger species, FL: 3.4–3.7 mm, elytral spots as long as wide. BL: 6.2–7.2 mm. Habitus: Fig. 2 ; sexual characters: Figs. 9–16. China (Yunnan), Laos.................................................................. D. flavoculatus Puthz

Figures

FIGURES 1–6. Habitus. 1 Dianous bimaculatus 2 D. flavoculatus 3 D. hubeiensis 4 D. hainanensis 5 D. siamensis 6 D. strabo. Scale bars: 1mm.

FIGURES 34–40. Sexual characters of Dianous siamensis. 34 male tergites IX and X 35 male sternite VIII 36 male sternite IX 37 aedeagus 38 female tergites IX and X 39 female sternite VIII 40 valvifers. Scale bars: 0.25mm.

FIGURES 17–24. Sexual characters of Dianous hubeiensis. 17 male tergites IX and X 18, male sternite VIII 19 male sternite IX 20, 21 aedeagus 22 female tergites IX and X 23 female sternite VIII 24 valvifers. Scale bars: 0.25mm.

FIGURES 25–33. Sexual characters of Dianous hainanensis. 25 male tergites IX and X 26 male sternite VIII 27 male sternite IX 28 aedeagus (Hainan) 29 aedeagus (Yunnan) 30 female tergites IX and X 31 female sternite VIII 32 valvifers (Hainan) 33 valvifers (Yunnan). Scale bars: 0.25mm.