Simuliid

Simuliid refers to any member of the family Simuliidae, commonly known as black flies or buffalo gnats. The family includes about 1,800 described species, with Simulium being the largest and most economically significant genus. Adults are small and hump‑backed, typically 1–5 mm long, with short antennae and clear wings that are often darkened by venation. They are strong fliers and commonly form swarms near breeding sites.

Life cycle and habitat are tied to aquatic environments. Immature stages are aquatic and require clean, fast‑flowing water. Females lay eggs on submerged substrates; larvae attach to rocks or vegetation and feed by filtering organic matter, while pupae are mobile within a protective case. After metamorphosis, adults emerge in swarms, and mating occurs on the wing. Depending on species and conditions, the complete cycle can take several weeks to months.

Feeding behavior is dimorphic. Females are hematophagous and seek vertebrate blood meals to produce eggs; males feed mainly on nectar. Bites can be painful and provoke irritation, dermatitis, or allergic reactions in some people. Some species are seasonal or diurnal and are most problematic near their breeding streams.

Medical and veterinary relevance is notable because simulids are vectors of pathogens. Most prominently, they transmit Onchocerca volvulus, the parasite that causes human onchocerciasis (river blindness), by taking blood meals from infected individuals. They can also play roles in the transmission of other filarial parasites in animals. Control efforts focus on larval habitat management and targeted larviciding (for example, Bacillus thuringiensis israelensis) to reduce adult populations, along with personal protective measures to limit bites. Simuliids occur worldwide, with greatest abundance in tropical and subtropical regions near rivers, streams, and other flowing waters.