Key for the identification of Chaetonerius Hendel from the East African islands

1 Occiput lateral and postgena in a right angle on meeting point with occiput posterior (Fig. 14). Face blackish-brown. Proepis- ternum inflated. Fore coxa mostly brown. Palpus brown............................... C. kirkspriggsi sp. n. (Fig. 16). - Occiput lateral and postgena curved on meeting point with occiput posterior. Face mostly to completely yellow. Proepisternum flattened. Fore coxa yellow. Palpus yellow.................................................................. 2

2. Underdeveloped antennal base present (Figs 11, 12, indicated by an arrow). Abdomen brown on males and brown with one median longitudinal yellow stripe on females............................................ C. ebejeri sp. n. (Fig. 17).

- Antennal base completely absent. Abdomen brown with two median longitudinal yellow stripes....................... 3

3. Mid and hind coxae yellow. Face dark yellow with median sagittal brownish-yellow to blackish-brown stripe (Fig. 3). Katepisternum brown ventrally with dorsal half paler to completely yellow................... C. alluaudi (Giglio-Tos) (Fig. 18).

- Mid and/or hind coxae brown. Face dark yellow with no sagittal blackish-brown stripe, at most with a median darkening, not contrasting. Katepisternum completely brown............................................................... 4

4 Thorax dorsally with one median brown V-shaped stripe. Mid and hind coxae brown. Cercus parallel sided with rounded apex, which has very long and thick setae resembling claws (Fig. 25)....................... C. madagasikara sp. n. (Fig. 19).

- Thorax dorsally with V-shaped brown stripe partially divided medially by one gray pruinose narrow stripe; in some cases, the brown stripe fades posteriorly. Mid coxa partially to completely brown and hind coxa yellow. Cercus narrowing distally with slightly pointed apex and sparse, thin and short setae (Fig. 24)............................. C. kotrbae sp. n. (Fig. 20).