Midge
A midge is any small fly, including species in several families of non-mosquito nematoceran Diptera. Midges are found on practically every land area outside permanently arid deserts and the frigid zones. Some midges, such as many Phlebotominae and Simuliidae, are vectors of various diseases. Many others play useful roles as prey for insectivores, such as various frogs and swallows. Others are important as detritivores, and form part of various nutrient cycles. The habits of midges vary greatly from species to species, though within any given family midges commonly have similar ecological roles.
Examples of families that include species of midges include:
- Blephariceridae, net-winged midges
- Cecidomyiidae, gall midges
- Ceratopogonidae, biting midges
- Chaoboridae, phantom midges
- Chironomidae, non-biting midges
- Deuterophlebiidae, mountain midges
- Dixidae, meniscus midges
- Scatopsidae, dung midges
- Thaumaleidae, solitary midges
Examples
The Ceratopogonidae include serious blood-sucking pests, feeding both on humans and other mammals. Some of them spread the livestock diseases known as blue tongue and African horse sickness - other species though, are at least partly nectar feeders, and some even suck insect bodily fluids.Many midges are known for having symbiotic relationships with many other organisms. These can be commensal, parasitic or mutualistic relationships. Many of the commensal relationships are found within the family Chironomidae.
Other ceratopogonid midges are major pollinators of Theobroma cacao. Having natural pollinators has beneficial effects in both agricultural and biological products because it increases crop yield and also density of predators of the midges.
The term "midge" is a vague term that refers to a large and diverse group of organisms. Although many are known as "bloodsuckers," there are many different roles that they play in their respective ecosystems. There is, for example, no objective basis for excluding the Psychodidae from the list, and some of them are blood-sucking pests and disease vectors.
Most midges, apart from the gall midges, are aquatic during the larval stage. Some Cecidomyiidae are considered significant pests of some plant species. The larvae of some Chironomidae contain hemoglobin and are sometimes referred to as bloodworms.
Non-biting midge flies are commonly considered a minor nuisance around bodies of water. In May 2025, a large emergence of midges caused mayhem at the World Exposition in Osaka, Japan.