Classification Tabanidae is in order Diptera, class Insecta, phylum Arthropoda.
Some tropical species have two or three generations per year.
Most are predacious upon other insect larvae, or feed on decaying plant material. The presence of these flies in very large swarms around cattle can cause the loss of so much blood that there is a large drop in the milk yield and a deterioration in their condition. Tabanids rarely attempt to engorge from any one feed, but seem to prefer to take frequent sips, often from different animals. The disease organisms of anaplasmosis, anthrax, tularemia, trypanosomiasis, swamp fever of horses, and vesicular stomatitis are known to be mechanically transmitted in this way by tabanids. Chrysops species are also the vectors of loa loa to humans and monkeys in West and Central Africa.