BRACHYCERA, Tabanomorpha, Tabanoidea Number of British species: 3

Size: L

Difficulty: 1

Scheme: Covered by the Larger-Brachycera recording scheme

Medium sized (7.5-10 mm), brownish to black flies, usually with banded markings on the abdomen. Body densely set with short erect bristles. Ocelli present; eyes in male nearly holoptic, in female dichoptic; antenna short, third segment reniform; mouthparts powerful, at most as long as the height of the head. Wing long and wide, often with dark markings; veins R₁ and R₂₊₃ ending in the costa at the same point; cell m₃ open; cell cup closed; legs relatively long; tibiae of mid and hind legs with apical spurs; empodium pulvilliform.

The larvae are aquatic and prey on larvae of other water insects. Prior to pupation, they move to nearby land. Adults are always encountered near running water, usually on the vegetation close by. Eggs are deposited in suitable spots over the water, such as bridges and overhanging branches. In some species, all females deposit their eggs together before they die. These clusters of eggs and dead flies may include up to several tens of thousands of females. The adults largely feed on nectar but some species feed on blood of humans and cattle.

Drake (1991), Oldroyd (1969), Stubbs & Drake (2001)