Key to Chinese species of Japanagallia (male)
1. Male pygofer with a row of serrate processes on caudomesal margin ........................................... J. dentata Cai & He
- Male pygofer not as above............................................................................................................................................ 2
2. Male pygofer with inner processes ............................................................................................................................... 3
- Male pygofer without inner processes ......................................................................................................................... 5
3. Aedeagal shaft compressed with pair of short processes ......................................................... J. tappana (Matsumura)
- Aedeagal shaft cylindrical with two pairs of long processes........................................................................................ 4
4. Aedeagal shaft stout, apex rounded with pair of stout processes ..................................................... J. spinosa sp. nov.
- Aedeagal shaft thin, apex hooked without such processes ......................................................... J. hamata Zhang & Li
5. Dorsoposterior corner of male pygofer with ventrally directed spine; aedeagus U-shaped in lateral view, shaft with pair of arcuate lamellate processes near base ................................................................................ J. lamellata sp. nov.
- Male pygofer and aedeagus not as above ..................................................................................................................... 6
6. Male pygofer with sharp projection on dorsomesal margin, caudal lobe triangular; aedeagal shaft with pair of basal processes on dorsal margin ....................................................................................................... J. pteridis (Matsumura)
- Male pygofer without such projection on dorsomesal margin, caudal lobe digitiform; aedeagal shaft with three sub- apical processes on dorsal and ventral margins ................................................................................. J. longa Cai & He