Key to males of Kapsa (Rigida) Cao & Zhang sgen. n.

1. Anal tube appendage rudimentary, small, not hooked at apex...................... K. apicispina Yang & Zhang sp. nov.

- Anal tube appendage well developed, hooked apically (Figs 5 b, 6b, 8b, 9b, 10e, 11c, 12c, 13c)........................ 2

2. Anal tube appendage curved cephalad in larteral view................................ K. maculata Sohi & Mann, 1992

- Anal tube appendage curved caudad in lateral view (Figs 5 b, 6b, 8b, 9b, 10e, 11c, 12c, 13c)........................... 3

3. Aedeagus without ventral process near base of shaft (Figs 5 h, 6g, 11i, 13g)........................................ 4

- Aedeagus with unpaired ventral process near base of shaft (Figs 8 h, 9g, 10j, 12i)................................... 7

4. Aedeagal shaft with ventral process near apex (Figs 6 g, 13g)................................................... 5

- Aedeagal shaft without process (Figs 5 h, 11i)............................................................... 6

5. Paramere forked apically, with apical and basal branch, aedeagal shaft with small thornlike process ventro-apically (Fig. 6 e, g)...................................................................... K. aculeiformis Cao & Zhang sp. nov.

- Paramere bifurcated apically, with dorsal and ventral branch, aedeagal shaft with large serrated protrusion ventro-medially (Fig. 13 e, g)................................................................ K. serrata Cao & Zhang sp. nov.

6. Apex of paramere straight, aedeagal shaft expanded in lateral view (Fig. 11 f, i)......... K. imminuta Yang & Zhang sp. nov.

- Apex of paramere sinuate, aedeagal shaft not expanded in lateral view (Figs 5 e, f, h).......... K. alba Dworakowska, 1981

7. Ventral process not extended to midlength of aedeagal shaft (Figs 8 h, 9g)......................................... 8

- Ventral process surpassing midlength of aedeagal shaft (Figs 10 j, 12i)........................................... 10

8. Paramere footlike apically, heel expanded, ventral processes of aedeagus rounded in lateral view (Fig. 9 e, g)...................................................................................... K. explanata Cao & Zhang sp. nov.

- Paramere with second extension apically, ventral processes of aedeagus pointed in lateral view (Fig. 8 h, i)............... 9

9. Aedeagal shaft expanded in lateral view, almost straight............................... K. minuta Dworakowska, 1994

- Aedeagal shaft not expanded in lateral view, obviously curved ventrad (Fig. 8 h)........... K. brevis Cao & Zhang sp. nov.

10. Ventral process of aedeagus with broadened and concave apex in caudal view....... K. borealis Dworakowska & Sohi, 1978

- Ventral process of aedeagus pointed apically in caudal view (Figs 10 k, 12j)....................................... 11

11. Paramere forked apically (Fig. 10 h).............................................. K. furcata Cao & Zhang sp. nov.

- Paramere not forked apically (Fig. 12 g)................................................................... 12

12. Aedeagus with base of ventral process broader than that of shaft in lateral view (Fig. 12 i).................................................................................................. K. megaprocessa Cao & Zhang sp. nov.

- Aedeagus with base of ventral process slightly narrower than that of shaft in lateral view......................................................................................... K. simlensis Dworakowska, Nagaich & Singh, 1978