Control of chironomid (Diptera: Chironomidae) infestations of aquatic systems

Aquatic insects in the dipteran family Chironomidae (non-biting midges) occasionally reach nuisance levels in water supply reservoirs, wastewater and drinking water treatment facilities, enclosed water supplies, and in recreational lakes. Nuisance emergences of adult midges can interfere with work activities by treatment plant personnel, can severely restrict outdoor recreational activities, and in some cases can cause allergic reactions and respiratory problems in humans. Larval midges, however, pose no health risk but result in aesthetic issues when found in industrial and municipal water supplies. Various methods are available to eliminate or reduce nuisance populations of chironomids from these types of aquatic habitats. These methods include engineering alterations, flushing, and several biocontrol techniques. The choice of the most appropriate method requires an understanding of the biology of the nuisance organism and must consider the type of system infested and the restrictions imposed by state and federal laws. Some of the most commonly used chironomid control measures will be discussed by using case studies from throughout the United States where chironomids have been successfully controlled.