Key to species of male Fistulatus
1 Pygofer with two pairs of processes ............................................................................................................................. 2
- Pygofer with one pair of processes ............................................................................................................................... 3
2 Aedeagal shaft with pair of flangelike processes ........................................................................................... F. luteolus
- Aedeagal shaft with two pairs of slender processes ........................................................................... F. quadrispinosus
3 Aedeagal shaft with two pairs of processes ............................................................................................... F. bidentatus
- Aedeagal shaft with one pair of processes or flanges................................................................................................... 4
4 Style with an apical extension ...................................................................................................................... F. sinensis
- Style without an apical extension ................................................................................................................................. 5
5 Pygofer with processes directed medially; aedeagus with shaft relatively straight in lateral view ........... F. rectilineus
- Pygofer with processes directed ventrally; aedeagus with shaft curved dorsally in lateral view ................................. 6
6 Connective with lateral processes; style with apical process slightly curved laterally, digitate ...................... F. athena
- Connective without lateral processes; style with apical process strongly curved laterally, footlike .............................. ............................................................................................................................................................. F. monkoboensis