Non-Biting Midge Flies
This article was written by Gail Griffin, Extension Master Gardener Volunteer for North Carolina Cooperative Extension in Lee County.
Do you have non-biting midge flies at your house? If you are experiencing swarms of insects flying around your porch lights and they don’t quite look like mosquitoes, your visitors may be non-biting midge flies. They can be mistaken for mosquitoes, but they are more slender in appearance. They are sometimes called ‘blind’ mosquitoes because they do not bite. They belong to the species Chironomids and are a cousin, once removed, of the biting midges we refer to as “no-see-ums”, which defy description.
Non-biting midge flies are found in streams, deep ditches, lakes, ponds and slow-moving rivers. Their life span is spent in or near water. Midge flies are a beneficial organism as a food source for fish and aquatic insects. However, large populations can indicate evidence of excessive organic matter located in bodies of water. Midge flies can tolerate increased levels of nutrients and pollution that other invertebrates cannot. As a result, their numbers can
explode. Runoff from fertilization of fields and lawns and gardens can create excessive amounts of nutrients. Wetter than normal conditions can also contribute to a reduction in water quality.
Midge fly eggs are laid in masses on the water surface and sink to the bottom where they hatch. The larvae feed on organic material found in sediment and in the water. The larvae transform into pupae and swim to the surface. The adults emerge in late March or early April. They mate in swarms and live three to five days while females lay their egg masses. The life cycle repeats itself every two to three weeks until fall. Several thousand adults per square yard can emerge in a single night, depending on water temperature. They are attracted to lights
and may accumulate on plants, around windows and walls outside of homes. They can become a nuisance when large numbers emerge.
To help keep water quality in check, don’t over fertilize your lawn or garden. Only use the amount recommended in your soil test results and avoid application when heavy rain is expected. Limiting outdoor lighting or relocating lighting away from residences may help reduce swarms during emergence. Commercial sprays used for control of mosquitoes may be useful, but only temporarily.
If non-biting midge flies are bugging you, the solution may be as simple as turning off the lights. Besides, you’re messing up the dark.
For more information on non-biting midge flies, go to content.ces.ncsu.edu/biology-and-control-of-non-biting-aquatic-midges or visit our local extension website at lee.ces.ncsu.edu
Gail Griffin is an Extension Master Gardener Volunteer for North Carolina Cooperative Extension in Lee County.