1     Coxae pale yellow; evaporative surfaces pale yellow to brown-grey with contrasting black punctures

2

–     Coxae fuscous to black; evaporative surfaces black with concolorous punctures

3

2(1) Dorsal surface of head and propleura mostly black with concolorous punctures

trilineata (Kirby)

–     Dorsal surface of head and propleura with large areas of pale yellow to brown with black punctures

undata (Say)

3(1) Apex of head broadly rounded, arcuate; dorsal surface of head distinctly concave, thickly clothed with short inward-curving hairs

–     Apex of head more tapering, narrowly rounded; dorsal surface of head not distinctly concave, or if somewhat concave then lacking short hairs

4(3) Boundary between dark surface of abdominal venter and pale lateral callus relatively straight, sharp; trochanters dark fuscous; scutellum lacking medial pale line

–     Boundary between dark surface of abdominal venter and pale lateral callus diffuse, not well defined; trochanters pale; scutellum usually with medial pale line