Robber flies eat biting flies and other flying insects like bees, butterflies and wasps. This species likes bees and dragonflies best as well as biting flies. During the day, they literally hang from branches or objects near the ground with their front legs, waiting to ambush passing prey. They are fast and noisy fliers, giving chase to insects that are already in flight. When they overtake them, they grab them with their legs to stop them from escaping. Once captured, the robber fly will stop at a branch or leaf and use its stiff mouth to pierce the body of its victim and then suck out the victim's insides.
They make a loud whirring noise as they fly because they beat their wings so quickly. They may be mistaken for a bee or a wasp because of their size and the buzzing noise they create.
Robber flies come in a variety of species. The ones from the Diogmites genus have a few color variations and different striped markings on the abdomen per individuals.
Common name: Robber Fly (Diogmites)
Scientific Name: Diogmites sp.
Adult Size (Length): 18mm to 40mm (0.71in to 1.57in) COMPARE
Identifying Colors: brown; red; green; black
General Description: fast, flying, buzzing, metallic, shiny
North American Reach (Though Not Limited To*): Alabama; Alaska; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Hawaii; Idaho; Illinois; Indiana; Iowa; Kansas; Kentucky; Louisiana; Maine; Maryland; Massachusetts; Michigan; Minnesota; Mississippi; Missouri; Montana; Nebraska; Nevada; New Hampshire; New Jersey; New Mexico; New York; North Carolina; North Dakota; Ohio; Oklahoma; Oregon; Pennsylvania; Rhode Island; South Carolina; South Dakota; Tennessee; Texas; Utah; Vermont; Virginia; Washington; West Virginia; Wisconsin; Wyoming; Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Nova Scotia; Ontario; Prince Edward Island; Quebec; Saskatchewan; Mexico
* Keep in mind that insect reach is not governed by lines on a map and therefore may appear in areas/regions/states beyond those listed above.