Simulidae

Simulidae, commonly known as blackflies, are a family of small, stout flies characterized by a humpbacked appearance and dark coloration. The family belongs to Diptera, suborder Nematocera, and comprises several genera, with Simulium being the largest and most widespread.

Simulids undergo complete metamorphosis. Eggs are laid in batches on aquatic substrates near fast-flowing streams. The aquatic larval stage attaches to submerged substrates and filters organic particles; they later become free-living pupae before emerging as winged adults. Adults are short-lived and typically form swarms for mating; females require a blood meal to develop eggs, while males primarily feed on nectar or do not feed.

Larval and pupal development depends on clean, well-oxygenated water and specific flow conditions; thus many species are indicators of good water quality. Distribution is worldwide, with higher diversity in tropical regions and specialist species in montane or fast-flowing rivers. Adult biting activity varies by species, with some preferring humans or animals and others feeding on wildlife.

Simulium species are important disease vectors, most notably Onchocerca volvulus, the parasite that causes river blindness in parts of Africa, Latin America, and Yemen. Vector status varies among species; not all bites transmit disease, but nuisance biting can be significant around rivers and streams. Control methods include environmental management and larviciding of breeding habitats with biological agents such as Bacillus thuringiensis israelensis or chemical larvicides, protective clothing, and repellents.