Skip to page content

FSC logo
Life in Freshwater


First  Previous    Random Species Browsing   Next  Last 

Tabanid larva

Horse flies are a slightly primitive group of very stout flies with large heads of which most is made up of the eyes. These display a wide range of colours. The very large Tabanus sudeticus has become fairly uncommon in recent years and is a large 3 cm fly. The genus Chrysops have yellow on the first few segments of the abdomen and a number of species are found. The Clegg ( Haematopota ) is very common and one of the smallest species at just over a centimetre. As a group they are large with around 160 species living in Europe. Most are associated with damp conditions and so are at their most abundant to the north and in upland areas. In Arctic and sub-arctic they can be painfully common, breeding near the pools of water that form with the melting of permafrost. Larvae live in wet soil or ponds and by the side of slow moving streams.

Horsefly Feeding
Adult Tabanid feeding on blood from a human arm (from the Arctic Region)

ECOLOGY: The group is very well known as biters of humans. They feed in a rather primitive way - not the stealth and precision of a mosquito. They circle the host, often with a deep drone. The smaller ones like the cleggs quietly alight. The proboscis is not much more than a "knife and sponge". They slit the skin and mop up the blood after releasing an anti-coagulant to stop it clotting. In the tropics they spread disease. Only the female drinks blood, for the development of the eggs. The males feed on nectar. The larvae are mainly aquatic and feed on a mix of organic matter and meat. They look a little like cranefly larvae.

Horsefly eyes closeup
Closeup of the colourful eyes of a living horsefly

See also Midges (Chironomids, Black Fly and Phantom) and Mosquitoes










Diptera - true flies

Looking for a next step?
The FSC offers a range of publications, courses for schools and colleges and courses for adults, families and professionals that relate to the freshwater environment. Why not find out more about the FSC?

Do you have any questions?

Site Statistics by Opentracker