midges

Midges are small flies in the order Diptera. The term is informal and covers several families rather than a single group, most notably the non-biting midges (Chironomidae) and the biting midges (Ceratopogonidae, including Culicoides). They occur worldwide, especially in moist environments such as wetlands, streams, ponds, and decaying vegetation, where many species have aquatic or semi-aquatic larval stages.

Like other flies, midges undergo complete metamorphosis. Eggs are laid in or near water; larvae hatch and typically feed on detritus, algae, or microorganisms, with Chironomidae larvae living in sediment and sometimes referred to as bloodworms because of their red hemoglobin-containing bodies. Pupation occurs in moist habitats, and adults emerge to mate. Adults are often short-lived; many non-biting midges do not feed, or consume only nectar or sugar, and may live only a few days to weeks. Biting midges are characterized by their small size and females’ blood-feeding behavior, which is required for egg production in many species.

Ecology and economic importance vary by group. Non-biting midges are an abundant part of aquatic and terrestrial food webs, serving as prey for fish, birds, and other animals, and their larvae help recycle organic matter while indicating water quality. Biting midges can be pests around lakes and livestock facilities; some species transmit pathogens to animals, such as bluetongue virus and African horse sickness virus. They can also cause dermatitis in humans in certain regions, though transmission of disease to people is less common than in animals.

Distribution is broad, with midges found in many climates and habitats. Management focuses on reducing breeding sites and habitat modification, complemented by targeted control measures when necessary.