Key to males of Ptychoptera species known from China

1. Rs not longer than r-m (fig. 3c, 5c)....................................................................... 2

- Rs at least 1.5 times length of r-m (fig. 1c, 7c, 9c)............................................................ 7

2. Wing with one brown band............................................. P. lii Kang, Yao et Yang, 2013 (Guizhou)

- Wing with two brown bands............................................................................. 3

3. Mesopleuron mostly brown (fig. 5a); epandrium yellow with caudal 1/2 brown (fig. 5a)....... P. circinans sp. nov. (Fujian)

- Mesopleuron uniformly yellow; epandrium uniformly yellow.................................................. 4

4. Gonostylus long and slender, about 1.5 times length of gonocoxite........ P. bannaensis Kang, Yao et Yang, 2013 (Yunnan)

- Gonostylus short, as long as gonocoxite (fig. 4c)............................................................ 5

5. Second tergum of abdomen mostly yellow; lobe on middle area of gonostylus slender, digitiform.................................................................................... P. lushuiensis Kang, Yao et Yang, 2013 (Yunnan)

- Second tergum of abdomen mostly brown; lobe on middle area of gonostylus board, tongue-shaped.................... 6

6. Abdomen with 5th and 6th terga dark brown, 6th and 7th sterna mostly brown (fig. 3a); tip of gonostylus with a hook-shaped dorsal lobe (fig. 4c).............................................................. P. emeica sp. nov. (Sichuan)

- Abdomen with 5th and 6th terga mostly yellow, 6th and 7th sterna yellow; tip of gonostylus with a digitiform dorsal lobe (Nakamura & Saigusa 2009).......................................... P. formosensis Alexander, 1924 (Taiwan; Japan)

7. Wing without band or cloud............................................................................. 8

- Wing with bands and clouds............................................................................. 9

8. Wing with r-m some distance before fork of Rs (fig. 9c); epandrium round at base, posterior margin with four pairs of papillate projections (fig. 10b); gonostylus simple, club-shaped (fig. 10c).......................... P. separata sp. nov. (Xizang)

- Wing with r-m close to fork of Rs; epandrium rectangular at base, posterior margin with one pair of digitiform surstylus; gonostylus with three lobes or projections................................... P. wangae Kang, Yao et Yang, 2013 (Yunnan)

9. Mesopleuron yellow.................................................................................. 10

- Mesopleuron black................................................................................... 11

10. Base of Rs with an elliptic cloud; sterna yellow.................. P. qinggouensis Kang, Yao et Yang, 2013 (Neimenggu)

- Base of Rs without cloud; sterna black..................................... P. clitellaria Alexander, 1935 (Sichuan)

11. Gonostylus much longer than gonocoxite..................................... P. xinglongshana Yang, 1996 (Gansu)

- Gonostylus not longer than gonocoxite................................................................... 12

12. Wing with an elliptic cloud at middle of CuA 1 ............................................................. 13

- Wing without cloud at middle of CuA 1 ................................................................... 14

13. Wing with R 4+5 obviously shorter than R 5; 2nd tergum of abdomen with base yellow.... P. bellula Alexander, 1937 (Jiangxi)

- Wing with R 4+5 equal to R 5; 2nd tergum of abdomen with base black......... P. gutianshana Yang et Chen, 1995 (Zhejiang)

14. Surstylus fused with epandrium; gonocoxite very board; hypandrium with a pair of yellow grooved projection........................................................................ P. longwangshana Yang et Chen, 1998 (Zhejiang)

- Surstylus not fused with epandrium; gonocoxite narrow; hypandrium with a wide membranous area................... 15

15. Terga of abdomen brownish black (fig. 7a); surstylus digitiform and broad basally, curved inwards at middle (fig. 8b).................................................................................... P. lucida sp. nov. (Xinjiang)

- Terga of abdomen dark brown with 2nd and 3rd terga mostly yellow (fig. 1a); surstylus flat and acinaciform, middle of inner edge slightly swollen (fig. 2b)................................ P. yankovskiana Alexander, 1945 (Neimenggu, Korea)