Eccritosia zamon
Unmistakable in the U.S. Thorax entirely dark brown to black. Abdomen black, then yellow with long yellow hairs, and then orange. Mystax completely yellowish with no black hairs. Rear tibiae and tarsi orange.
Size: 18-31 mm
Range: Primarily Arizona to Texas and south to Panama, but there are records from LA and FL
FL Range: One record from along the Blackwater River in the Panhandle
Season: June-October in U.S., Florida record is from July




References
Lamas-M, G. (1973). revision of Eccritosia Schiner, 1866 (Diptera, Asilidae). Sao Paulo Dep Zool Papeis Avulsos.