Key to males of Pristonesia

1. Posterior hypopygeal margin strongly excavated, so that median area of hypopygium occupies less than half of its length (Figs 4A, 4D, 4J, 5D)....................................................................................... 2

- Posterior hypopygeal margin weakly emarginated, so that median area of hypopygium occupies more than half of its length (Figs 4G, 5A, 5G)..................................................................................... 5

2. Anterior hypopygeal margin with anteromedial apodeme (Fig. 4D, 4J); median area of hypopygium at most quarter of its length (Figs 4D, 4J)......................................................................................... 3

- Anterior hypopygeal margin without anteromedial apodeme (Figs 4A, 5D); median area of hypopygium about third of its length (Figs 4A, 5D)........................................................................................ 4

3. Lobes of posterior hypopygeal margin outcurved, with small conical spine (Fig. 4D); harpe with median projection (Fig. 4F)....................................................................................... P. oracil sp. nov.

- Lobes of posterior hypopygeal margin angulate, without any spine (Fig. 1J); harpe without median projection (Fig. 4L)........................................................................................... P. querfil sp. nov.

4. Projection of harpe narrow in dorsal view (Fig. 4B); apical aedeagal setae about as long as harpe (Fig. 4C)....................................................................................................... P. nyamuragira

- Projection of harpe conical in dorsal view (Fig. 5E); apical aedeagal setae much shorter than harpe (Fig. 5F)................................................................................................... P. tainatril sp. nov.

5. Head subquadrate, about as long as wide (Fig. 2E); median clypeal lobe rounded (Fig. 2E); base of aedeagal apodeme strongly curved mesad (Fig. 5C).................................................................... P. sicril sp. nov.

- Head pentagonal or nearly so, longer than wide (Figs 1H, 3B); median clypeal lobe angulate (Figs 1H, 3B); base of aedeagal apodeme straight or nearly so (Figs 4H, 4I, 5H, 5I)........................................................... 6

6. Base of digitus strongly angled and projected (Figs 5H, 5I); harpe narrow with elongate apical projection in dorsal view (Figs 5H, 5I)................................................................................. P. uvenil sp. nov.

- Base of digitus smoothly curved (Figs 4H, 4I); harpe wide with conical apical projection in dorsal view (Figs 4H, 4I)............................................................................................ P. parcetil sp. nov.