Key to species of Periacma, Irepacma and Epiracma from Taiwan

1 Valva in male with a dorso-proximal process.............................................................. 2

- Valva in male without dorso-proximal process.............................................................. 3

2 Aedeagus with a hooked process medially........................................... Periacma aduncata sp. nov.

- Aedeagus without a hooked process....................................................... Periacma delegata

3 Apophysis anterioris in female absent.................................................................... 4

- Apophysis anterioris in female present................................................................... 5

4 Gnathos weakly sclerotized, nearly membranous........................................... Irepacma conioxantha

- Gnathos heavily sclerotized....................................................... Irepacma flagellata sp. nov.

5 Gnathos broadly subtriangular................................................. Epiracma longicaudata sp. nov.

- Gnathos annular................................................................. Epiracma annularis sp. nov.