Simuliidae (black-flies, buffalo gnats; order Diptera, suborder Nematocera)
Small family of small, stout flies which have short legs and elongated mouthparts. The wings are broad, with thickened anterior veins. The antennae are short, and 11-segmented, and ocelli
are absent. In males, the eyes are holoptic
. Females of some species are active blood-suckers, especially Simulium damnosum
of Africa, which carries the nematode Onchocera
, the cause of filariasis. Adults are never found far from running water, as their larvae are aquatic and prefer swift-flowing, well-oxygenated water. The larvae feed by filtering detritus and planktonic organisms from the water by means of a series of stout bristles around the mouth. The family has a world-wide distribution
and in some countries is of great economic importance. More than 1300 species have been described.