Key to Chinese species of genus Mydaea Robineau-Desvoidy, 1830 (males)

The following key is mainly based on Xue et al. (2014), where 7 other species recorded in China ( M. adhesipeda Xue, 2019; M. corni (Scopoli, 1763); M. quinquiseta Xue, 2019; M. qingyuanensis Xue, 2019; M. combiniseriata Xue, 2019; M. wusuensis Xue, 2019 and M. xishuiensis Wei, 2005) and one new species were included. M. flavifemora Feng, 2000, M. jiuzhaigouensis Feng & Deng, 2001 and M. scolocerca Feng, 2000 were three junior synonymies and have been excluded.

1. dc 2+3 .............................................................................................. 2

- dc 2+4 .............................................................................................. 7

2. Femora yellow....................................................................................... 3

- Femora black........................................................................................ 4

3. Parafacial about 3/5 of postpedicel in width; the longest hair of arista subequal to width of postpedicel; pra about 1/3 of posterior npl; basicosta black; fore tibia without medial pv; hind femur with complete pv row.................................................................................................... M. bideserta Xue & Wang, 1992

- Parafacial about 1/3 of postpedicel in width; the longest hair of arista about 1/3 of postpedicel in width; pra longer than posterior npl; basicosta yellow; fore tibia with 1 medial pv; hind femur without pv ....... M. jubiventera Feng & Deng, 2001

4. Hind femur with complete and developed pv row............................................................ 5

- Hind femur without pv ............................................................... M. shuensis Feng, 2003

5. Frons subequal to antennal postpedicel in width; frontal vitta disappeared at middle................................ 6

- Frons about twice as wide as antennal postpedicel; frontal vitta about twice as wide as fronto-orbital plate......................................................................................... M. laxidetrita Xue & Wang, 1992

6. Eyes with dense hair; frons with complete fr; parafacial about twice as wide as antennal postpedicel............................................................................................... M. gansuensis (Ma & Wu, 1992)

- Eyes bare; frons with partial fr; parafacial about half of antennal postpedicel in width........................................................................................................ M. franzosternita Xue & Tian, 2014

7. Scutellum yellow, or only distal part yellow................................................................. 8

- Scutellum dark black.................................................................................. 16

8. Hind femur without pv, or with pv at base at most............................................................ 9

- Hind femur with complete row of pv ..................................................................... 11

9. Postpronotal lobe black................................................................................ 10

- Postpronotal lobe yellow........................................................... M. tinctoscutaris Xue, 1992

10. Palpi and legs black................................................................ M. quinquiseta Xue, 2019

- Palpi yellow, but black at distal 1/4; legs yellow except tarsi black brown (Fig. 15)..................................................................................................... M. apicinigra Wang, Li & Yang, sp. nov.

11. Anterior spiracle yellow............................................................................... 12

- Anterior spiracle fuscous.............................................................................. 14

12. acr 0+2............................................................................................ 13

- acr 0+1....................................................................... M. qingyuanensis Xue, 2019

13. Coxae and trochanters yellowish brown; hind femur with strong and complete row of pv ........... M. gracilior Xue, 1992

- Coxae and trochanters black; hind femur with weak pv ..................................... M. corni (Scopoli, 1763)

14. Coxae, trochanters of fore leg and all tarsi fuscous........................................................... 15

- All legs yellow............................................................... M. kangdinga Xue & Feng, 1992

15. Ventral surface of fore femur fuscous on basal half..................................... M. setifemur Ringdahl, 1924

- Ventral surface of fore femur yellow on basal half..................................... M. combiniseriata Xue, 2019

16. All legs entirely black................................................................................. 17

- Legs not as above.................................................................................... 19

17. Frons subequal to the distance between outer margins of posterior ocellus....................................... 18

- Frons subequal to 1.5 times as wide as anterior ocellus..................................... M. wusuensis Xue, 2019

18. Antennal arista ciliated, the longest hair subequal with antennal postpedicel in width; pra about 3/4 of npl; fore tibia with 1 medial p; hind femur with pv; abdomen with shifting patches......................... M. sinensis Ma, Wu & Cui, 1986

- Antennal arista plumose, the longest hair about 1.5 times as wide as postpedicel; pra about 1.3 times as long as npl; fore tibia without medial p; hind femur without pv; abdomen without shifting patch..................... M. ancilloides Xue, 1992

19. Hind femur, or hind and mid femora, or all femora yellow.................................................... 20

- All femora fuscous................................................................................... 30

20. Hind femur with pv row............................................................................... 21

- Hind femur without pv ................................................................................ 25

21. pra about half of posterior npl in length; wing brown; basal half of hind femur with pv obviously..................... 22

- pra longer than posterior notopleural seta; wing yellow; hind femur with sparse and short pv ........................ 23

22. Frons about 2.0–2.5 times as wide as anterior ocellus; hind tibia with 2 av .................. M. brunneipennis Wei, 1994

- Frons subequal with anterior ocellus in length; hind tibia with 1 av ............................... M. nigra Wei, 1994

23. Frons less than 6 pairs of fr; pra longer than posterior npl; hind tibia with 2 av .................................... 24

- Frons with 10 pairs of fr; pra about 1.5–2.0 times as long as posterior npl; hind tibia with 3 av .... M. urbana (Meigen, 1826)

24. Tibia black brown; mid tibia with 3– 4 p. ................................................. M. glaucina Wei, 1994

- Tibia yellow; mid tibia with 2 p. ............................................ M. minutiglaucina Xue & Tian, 2012

25. Frons about twice as wide as anterior ocellus; abdomen without shifting patch.................................... 26

- Frons subequal to anterior ocellus in width; abdomen with shifting patches.................... M. discocerca Feng, 2000

26. Antennal arista ciliated, the longest hair subequal to width of antennal postpedicel................................. 27

- Antennal arista short ciliated, the longest hair longer than width of antennal postpedicel............................ 29

27. Parafacial subequal to postpedicel in width................................................................ 28

- Parafacial about half of postpedicel in width................................................. M. brevis Wei, 1994

28. Basicosta dark brown; pra approximately 1.3 times as long as posterior npl; fore tibia without median p; ventral surface of fore tarsus without adhesive hairs (special hair-like setae modified for climbing or gripping, proposed by Du et al., 2019)................................................................................... M. fuchaoi Xue & Tian, 2012

- Basicosta yellow; pra shorter than posterior npl; fore tibia with 1 median p; ventral surface of fore tarsus with adhesive hairs................................................................................. M. adhesipeda Xue, 2019

29. Fore femur yellow; metapleuron bare............................................... M. nigribasicosta Xue, 1996

- Fore femur black at basal half; metapleuron with hairs....................................... M. affinis Meade, 1891

30. Hind femur with pv ................................................................................... 31

- Hind femur without pv ................................................................................ 33

31. Hind femur with complete pv row; tibia yellow............................................................. 32

- Hind femur with pv at basal half; tibia brown............................................... M. nubila Stein, 1916

32. Frons subequal to twice of anterior ocellus; hind tibia with 1 av and 2 ad. .................... M. minor Ma & Wu, 1986

- Frons equal to the distance between outer margins of posterior ocellus; hind tibia with 2 av and 3 ad. .................................................................................................... M. latielecta Xue, 1992

33. kepst 2+2........................................................................................... 34

- kepst 1+2......................................................................... M. xishuiensis Wei, 2005

34. Frons subequal to the distance between outer margins of posterior ocellus; the longest aristal hair 2 times as wide as antennal postpedicel; tibia yellow; hind tibia with 1 av .................................... M. emeishanna Feng & Deng, 2001

- Frons about 1.6–2 times of anterior ocellus; the longest aristal hair about equal to antennal postpedicel in width; tibia brown to dark brown; hind tibia with 2–3 av ..................................................... M. subelecta Feng, 2000