Key to species of Afrotropical Syngenes

1. Taxa from Africa...................................................................................... 2

- Taxa from Madagascar and Indian Ocean Islands ............................................................. 6

2. Tibial spurs right-angular, with prominent internal flange (Figs 4, 5); biaereolate cells present in costal area of forewing before Rs (Fig. 3); abdomen with chevron-like pattern (Fig. 11). Eastern African coastal belt, South Africa to Somalia ............................................................................................. S. longicornis (Rambur) .

- Tibial spurs not sharply bent at a right angle, more evenly curved and lacking prominent triangular flanges............... 3

3. Biaereolate cells absent from costal area of forewing before Rs and rarely present before Rs2 (Fig. 27); unbroken series of biaereolate costal cells only commencing beyond Rs2; tibial spurs slender, strongly curved (but not bent at right angle), with slight flange in forelegs (Figs 28, 29); Central, South and Eastern Africa........................... S. medialis sp. nov.

- Biaereolate cells present in costal area of forewing before Rs or commencing at Rs with three or more before Rs2......... 4

4. Wings narrow relative to other Syngenes species (Figs 44, 45); body black with bright yellow markings (Figs 46, 51). Namibia and Northern Cape Province, South Africa.................................................... S. scholtzi sp. nov.

- Wings broad; unbroken series of biaereolate cells present in forewing costal area from before Rs2 to pterostigma. Central and West Africa........................................................................................... 5

5. Costal area with 1–2 biaereolate cell before Rs in each forewing (based only on the Holotype from Congo) (Figs 73, 74). Wings heavily marked............................................................. S. inquinatus (Gerstaecker) .

- Costal area with variable number of biaereolate cells (1–4) before Rs (based only on one syntype from Lagos, Nigeria), slender species, wings not heavily marked, spurs curved, slender (Figs 76, 77)......................... S. debilis (Gerstaecker) .

6. Forewing costal area with many (> 8) biaereolate cells before Rs.............................. S. dolichocercus Navás

- Forewing costal area with fewer (<6) biaereolate cells before Rs............................. S. maritimus (Needham)