6a. With different sized calypters, lower calypter is larger (Fig. 11); no hair on ventral surface of scutellum
(Fig. 12); wing vein A1+CuA2 does not reach the margin of
wing (Fig. 13)
Muscidae
6b. Calypters are approximately the same
size or lower calypter is smaller (Fig. 14); hair on ventral side of scutellum
(Fig. 15);
wing vein A1+CuA2 reaches margin of wing (Fig. 16)