Sybistroma Meigen, 1824

Grichanov, I. Ya., 2020, A new species of Sybistroma Meigen, 1824 (Diptera: Dolichopodidae) from China, Far Eastern Entomologist 418, pp. 1-8 : 3-4

Key to the species of Sybistroma Meigen from Sichuan and Yunnan (males)

This key builds extensively on Yang et al. (2011) but has scattered modifications based on material examined for the present study in ZIN collection, plus the inclusion of a new species.

1. Antenna with postpedicel rather short, as long as wide, obtuse apically ............................ 2

– Postpedicel elongated, distinctly longer than wide, acute apically .................................... 3

2. Postocular setae wholly black (Yunnan) ................. S. compressa (Yang et Saigusa, 2001)

– Middle and lower postocular setae yellow (Sichuan, Yunnan) ....... S. acutata (Yang, 1996)

3. Cercus nearly quadrate, with a big apical incision, or nearly triangular with obliquely concave outer margin ........................................................................................................ 4

– Cercus not as stated above .................................................................................................... 7

4. Hind femur with 1 long ventral bristle basally; cercus somewhat triangular, with obliquely incised outer margin (Sichuan) ............................................... S. emeishana (Yang, 1998)

– Hind femur without ventral bristles; cercus somewhat quadrate, with a big apical incision ... ............................................................................................................................................ 5

5. Middle and lower postocular setae pale; arista-like stylus with black swollen apex (Henan, Shaanxi, Sichuan) ........................................................................... S. flava (Yang, 1996)

– Postocular setae wholly black; arista-like stylus not swollen apically ................................. 6

6. Antenna with only basal ventral area of postpedicel dark yellow; postpedicel long (Sichuan) ...................................................................... S. binigra (Yang et Saigusa, 1999)

– Antenna with postpedicel wholly yellow; postpedicel short, triangular (Sichuan) ............... .............................................................................. S. longaristata (Yang et Saigusa, 1999)

7. Middle and lower postocular setae pale; lower calypter with yellow hairs ......................... 8

– Postocular setae wholly black; lower calipter with black hairs ............................................ 9

8. Postpedicel 2.4 times longer than wide; arista-like stylus with two dark swellings (Gansu, Ningxia, Sichuan, Shanxi) ............................................................... S. incisa (Yang, 1999)

– Postpedicel 2.9 times longer than wide; arista-like stylus with one black and white swelling (Yunnan) .................................................................................................... S. genriki sp. n.

9. Arista-like stylus subapical; antenna blackish with extreme base of postpedicel yellow (Sichuan) .............................................................................. S. sichuanensis (Yang, 1998)

– Arista-like stylus dorsal or subdorsal .................................................................................. 10

10. Thorax and abdomen partly yellow; postpedicel with additional arista-like process apically (Henan, Shaanxi, Yunnan) ........................................... S. biaristata (Yang, 1999)

– Thorax and abdomen metallic green (at most with metapleuron yellow); apex of postpedicel swollen, wholly black, without additional arista-like process (Yunnan) ............................. ............................................................................................... S. yunnanensis (Yang, 1998)