Robber Fly

Description:

Adult stages are medium to large (3/8 to 1-1/8 inch) flies often observed on stems of plants, on the ground or flying low. Species vary in appearance and some mimic wasps and bees. Most species are gray to black, hairy-bodied, have a long, narrow, tapering abdomen containing segments that may be banded, patterned or contrasting in color. The heads of adults have a depression between the eyes when viewed from the front. They have long, strong legs for grabbing prey.

Habitat:

Path in Miller Springs Park.

Notes:

Robber flies will eat almost any flying creatures they can catch. Some of their prey can be considerable larger than they are, and one’s daily diet may include everything from bees and wasps to grasshoppers, butterflies, beetles, and other flies. Most hunt from perches where they wait for passing prey, and some species actually establish a flight territory that they defend from other robber flies. They possess a mobile head that can move about in various directions. When seeing a passing prey, they will immediately give chase and catch it in mid-air. They may even fly ahead and intercept the prey from an angle. They will then fly to a shady perch, holding the prey in their long spiny legs, and consume their catch by sucking their prey dry with hypodermic-like mouthparts.