Onchocerciasis
Guides
Simulium
black flies, buffalo gnats, turkey gnats
Simulium is a large genus of black flies in the family Simuliidae, containing nearly 2,000 described species across 38 subgenera. Adult females are obligate blood-feeders that use blade-like mandibles to slice skin and lap pooled blood, while males feed on nectar. The genus includes significant disease vectors, most notably species that transmit Onchocerca volvulus, the nematode causing human onchocerciasis (river blindness). Larval stages are strictly aquatic, inhabiting fast-flowing streams and rivers where they filter-feed using specialized cephalic fans.