Key to the species of Acanthocaudus (based on females)

1. Mesosoma and metasoma entirely yellow (Figs 2, 5)............................ Acanthocaudus caudacanthus (Smith)

- Mesosoma and metasoma with at least some brown coloration (Figs 1, 3–4, 6–7)...................................2

2. Mesosoma yellow except mesonotum brown (Fig. 1); head either yellow with ocellar triangle entirely brown to black (50%) or yellow with brown to black markings around periphery of each ocellus (50%)..... Acanthocaudus bicolor Kula, new species

- Mesosoma mottled yellow and brown (Fig. 6) or entirely brown (Fig. 7), propleuron, pronotum, mesoscutum peripherally, mesopleuron peripherally, metapleuron, and propodeum with varying extent of yellow when mesosoma is mottled; head entirely brown or brown dorsally and gradually transitioning to yellow ventrally.............. Acanthocaudus tissoti Smith