Non-biting midge flies or chironomids commonly occur in inland and coastal natural and man-made bodies of water. These midges are commonly known as “blind mosquitoes” because they are mosquito-like but do not bite. Midges are also called “fuzzy bills” because of the male’s bushy antennae. These aquatic insects are tolerant of a wide range of environmental conditions. Chironomid midges are found in swift moving streams, deep slow moving rivers, stagnant ditches, and in lakes and ponds that are rich in decomposing organic matter. The presence of certain chironomid midges is often used as an indicator of water quality.
Bodies of water in urban and suburban areas are subjected to intensive human use through residential, recreational and agricultural activities. Through runoff, these ponds and lakes often become exceedingly rich in nutrients. Consequently, the variety of organisms in such habitats is usually low with just a few pollution tolerant species developing large populations. Some species of chironomid midges that are tolerant of low dissolved oxygen conditions often are a major component of the bottom invertebrate organisms of urban and suburban lakes, ponds and storm water retention ponds.
Most species of chironomid midges are highly desirable organisms in aquatic habitats. Midges are an important food source for fish and predatory aquatic insects. Larvae “clean” the aquatic environment by consuming and recycling organic debris.
In urban environments where homes are constructed adjacent to lakes and ponds, adult midges often emerge in extremely large numbers, causing a variety of nuisance and other problems for people who reside within the flight range of these insects. Adults are weak flyers and may fly or be blown ashore where they congregate on vegetation, under porch alcoves in carports and on walls of homes and other buildings. Swarms of adults may be so dense that they interfere with outdoor activities and stain walls, cars and other surfaces upon which they rest. Adults are attracted to lights and may accumulate in large numbers on window screens and around porch and street lights. The occurrence of midges promotes the growth of spiders whose unsightly webs may have to be removed frequently.
Chironomid midges are one of the most common and most abundant organisms in natural and man-made aquatic habitats. Larvae are found in small and large natural lakes, sewage oxidation and settling ponds, residential lakes and ponds, and slow moving shallow rivers. Densities of over 4,000 larvae/ft 2 often occur on the bottoms of nutrient rich bodies of water. During emergence periods, it is not unusal for several thousand adults per square yard of surface to ermerge on a nightly basis. Needless to say, midges emerging from these bodies of water may cause severe nuisance and other economic problems.