Key to species of the Stenus cirrus group in Fujian

1 Body larger, BL> 3.4 mm; interstices of head and pronotal punctation without reticulations........................... 3

- Body smaller, BL≤ 3.4 mm; interstices of head and pronotal punctation distinctly reticulations........................ 2

2 Pronotum longer than broad, without median longitudinal furrow; punctation of pronotum and elytra less confluent. Habitus: figs. 3, 4. Sexual characters: figs. 15–20. BL= 3.2–3.4 mm ...................................... S. fujianensis sp.n.

- Pronotum nearly as long as broad, with long median longitudinal furrow; punctation of pronotum and elytra very confluent. Habitus: fig. 10. Sexual characters: figs. 15–16 in Puthz, 2003. BL: 2.6–3.4 mm. China (Jiangxi)................................................................................................ S. huangganmontium Puthz, 2003

3 Elytra with spots indistinct. Habitus: figs. 1, 2. Sexual characters: figs. 11–14. BL= 3.5–3.7 mm ......................................................................................................... S. mangdangshanus sp.n.

- Elytra with spots distinct................................................................................ 4

4 Punctation of pronotum and elytra less dense and well delimited; punctation on elytral spot very sparse. Habitus: figs. 5, 6. Sexual characters: figs. 21–26. BL: 3.2–4.2 mm ........................................ S. cooterianus Puthz, 2003

- Punctation of pronotum and elytra very dense and confluent, that of the pronotum irregular........................... 5

5 Punctation of elytra very densely crowded; elytral spot slightly longer than half elytron length. Habitus: fig. 5. Sexual characters: figs. 19–20 in Puthz, 2003. BL: 3.5–4.7 mm .................................... S. lacrimulus L. Benick, 1942

- Punctation of elytra less dense, less crowded; elytral spot shorter than half elytron length. Habitus: figs. 7, 8. Sexual characters: figs. 27–32. BL: 3.6–4.3 mm ........................................................ S. wuyiensis Puthz, 2003