Key to Chinese species of Commatarcha
1 Forewing with R4 and R5 stalked basally (Fig. 26)................................................ C. angustiptera
- Forewing with R4 and R5 not stalked..................................................................... 2
2 Forewing with a large irregular white marking............................................................. 3
- Forewing without a white marking....................................................................... 6
3 Forewing with large white marking dorsodistally extending to costal margin of subapex (Diakonoff 1989: 34, Fig. 22A)............................................................................................ C. citrogramma
- Forewing with large white marking not extending to costal margin dorsodistally.................................. 4
4 Ostium bursae with posterior margin deeply incised (Diakonoff 1989: 28, Fig. 32A)....................... C. quaestrix
- Ostium bursae with posterior margin rounded.............................................................. 5
5 Ostium bursae with anterior margin shallowly concave (Fig. 22).................................... C. fanjingshana
- Ostium bursae with anterior margin triangularly and deeply incised (Fig. 21)..................... C. convoluta sp. nov.
6 Aedeagus shorter than distance from apex of uncus to distal part of saccus....................................... 7
- Aedeagus longer than distance from apex of uncus to distal part of saccus....................................... 8
7 Forewing with an inverted V-shaped ochreous yellow spot at basal 1/3 of costal margin (Fig. 12).......... C. palaeosema
- Forewing without such an ochreous yellow spot (Fig. 11)....................................... C. hamata sp. nov.
8 Valva with two rounded apical lobes...................................................................... 9
- Valva without apical lobes............................................................................. 10
9 Aedeagus setose distally (Fig. 20)..................................................... C. setiferaedeaga sp. nov.
- Aedeagus without setae (Diakonoff 1989: 33, Fig. 34A)........................................... C. chrysanches
10 Uncus with posterior margin cracked.................................................................... 11
- Uncus with posterior margin uncracked (Fig. 15)................................................... C. acidodes
11 Valva sub-triangular, narrowly rounded at apex (Fig. 16).......................................... C. guangxiensis
- Valva sub-rectangular, obtusely rounded at apex (Fig. 19).................................. C. rotundivalva sp. nov.