Adult midges are a group of tiny-winged flies that at first glance resemble mosquitoes. Midges can be distinguished from mosquitoes through their small mouthparts that are not elongated into a piercing-sucking structure for blood feeding. So, unlike mosquitoes, midges do not bite. Larvae of midges are aquatic, and adults are usually found flying in swarms around ponds or streams in the late afternoon and evening.
Midges undergo complete metamorphosis, meaning that they develop through four life stages: egg, larva, pupa, and adult. The females can produce over 1000 eggs depending on the species. They lay their eggs in aquatic habitats over or under the surface of the water or on emergent plants. Eggs hatch into larvae within a few days to one month depending on the species and environmental conditions. Larvae develop in water into pupae within four weeks to four years. The pupae often stay sheltered in debris, attached to the substrate, or produce a cocoon. The pupal stage is short and takes from a few hours to two weeks. Upon completion of development, it swims to the water’s surface and the adult emerges from the pupa. In most species, many adults simultaneously emerge from the pupae, producing swarms of midges. In most species, adults live only for a few days to a few weeks. They generally do not feed but may drink water or nectar. Most midge species have one or two life cycles per year. However, in colder regions, it may take over a year to complete a life cycle.
In residential settings, particularly houses built around lakes and ponds, adult midges often emerge in very large numbers, causing nuisance problems for people within the flight range of these insects. Swarms of adults may be so dense and annoying while people are doing their outdoor adventures. Also, they stain walls, cars, and other surfaces upon which they rest.
Fertilizer run-off from residential lawns and gardens into lakes, ponds, and streams make nutrient-rich habitats for midges causing the development of nuisance-level populations. Therefore, proper use of fertilizers can lessen excess run-off into lakes and ponds reducing midge populations.
