Green Commas are certainly tough themselves, overwintering as an adult, but they’re no match for a robber fly. Perfectly described in the Kaufman Field Guide to North America, robber flies “are to other insects what falcons are to other birds: swift predators on the wing.” They perch in open habitat waiting for flying prey. Once in their sights, the chase is on. A swift injection of toxins from a piercing-sucking beak immobilizes, and digestive enzymes allow the fly to suck the contents. Their larvae are also predators, but live and hunt in the soil. Kristi’s picture beautifully captures some of the adult characteristics: a long and slender body, with a tapering abdomen, a “beard,” large eyes with a trough between the tops, and long legs with thick spines.
Photo by Kristi DuBois on 9/11/20 near Fish Creek in Mineral County, MT