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