Information on midges around the water:
- The flying insects making up the swarms seen around the lake shore are called midges
- Midges are flies, specifically flies in the family Chironomidae
- Hundreds of species of chironomid midges are found in southern Ontario
- Most species of chironomid midges are highly beneficial and desirable organisms in aquatic habitat
- Chironomid midges look like mosquitoes, and are closely related to them, but midges don’t bite
- The larvae of midges live in the water, feeding on plants and other organic debris
- Adult midges are short-lived and don’t eat
- Adult midges emerge from the water in large numbers in the spring and form mating swarms
- This happens every year, usually in the first week of May
- Swarms are larger in some years, based on weather conditions in the previous fall and winter
- The numbers of midges will go down within a week or two
- Midges go through several generations a year, and are present all summer
- Large swarms of midges are often also seen in the fall, although spring numbers are usually larger
- Midges are attracted to lights at night
- Residents are advised to keep windows and doors closed, and to turn off outdoor lights at night
- Midges are an important food source for fish, aquatic insects, birds, and other wildlife
- Larval midges play an important role by eating organic debris, cleaning up the water
Overall, Credit Valley Conservation does not advise using insecticides in natural ponds and lakes or in Storm Water Management ponds to control chironomids.
If you would like more information, please email ecology@cvc.ca.