n.
Any member of the dipteran genus Tabanus or, more generally, of the family Tabanidae.
These stout flies range from as small as a housefly to as large as a bumblebee . Sometimes called greenheaded monsters, horseflies have metallic or iridescent eyes. Adults are fast, strong fliers usually found around streams, marshes, and wooded areas. They may carry animal diseases, including anthrax , tularemia, and trypanosomiasis. The bites of the bloodsucking females can be painful, and a swarm may suck more than 3 oz (about 90 ml) of blood a day from an animal. Males feed on nectar, honeydew, and plant sap. Horseflies of the genus Chrysops , usually called deerflies, are smaller and have dark markings on the wings.