During spring and early summer, the District sometimes gets reports of flying insect swarms. These insects look a lot like mosquitoes, but are actually a different type of insect: non-biting midges.
Midges are small insects that look an awful lot like mosquitoes until you look at them up close. They both have long bodies and long narrow wings, but there are some key differences that set midges apart. If you were to get out a magnifying glass and look at a mosquito, you would see that the edges of the wings of a mosquito are covered in scales that look like fine hairs. You would also be able to see that mosquitoes have a long needle-like mouth (a proboscis). Midges have neither of these. Their wings look like barren panes of glass and they don’t have the long proboscis, which means that they cannot bite.
The good news is that these midges don’t bite, don’t carry any diseases, and are harmless to humans. This is why we don’t control their numbers. The bad news is that, as many of you have already found out, they can be really annoying! They’re often seen in large swarms, and may gather around outdoor lights or on the sides of buildings.
Midges live most of their lives as worm-like larvae at the bottom of water sources, but every spring, if the weather is warm and there is a lot of fresh water available, they will make the transition to adults. The midge larvae drift slowly up from the bottom and rest on the water surface to pupate and prepare to take to the sky. As pupae, they are an excellent food source for fish, frogs, newts, and even other insects like water boatmen, dragonflies and water striders. When they become adults, they lose the ability to eat or drink and will live only 3 days before they starve to death. To maximize the chance of finding a mate in that short time, the midges will rise together in huge numbers called “mating swarms” which may be blown into shore to rest on buildings, windows, or plants. They are particularly attracted to light sources, so porches with lights are a favorite place to hang out!
There isn’t an easy way to get rid of the midges, but as everything dries up you should see fewer and fewer of them. The swarms will die out in just a few weeks, and in the meantime, they’re an incredible source of food for the babies of birds like swallows, swifts and hummingbirds. While you wait for their numbers to decrease, you may be able to get some relief by turning off outdoor lights, especially those close to doors and windows. You should also keep your doors and windows screened or closed to keep midges from coming into your home. Bug zappers (blacklight traps) will attract and kill midges, but might end up making things worse by attracting additional midges to the area.
However, if you notice that you’re being bitten, please give us a call! You may also have mosquitoes in your area, and that’s a problem we can help with. Let us know if you’re experiencing mosquito bites, and we’ll send a technician to check out the area for any mosquito breeding sources.
Page last reviewed: December 28, 2023