We occasionally get fruit flies in the house in small numbers that soon disappear. But the last couple of years, in the fall, we have had a terrible problem with fruit flies, and we can’t seem to get rid of them. More keep appearing. Why do they seem to be more of a problem in the fall?

N. N., Malden, MA

It’s not your imagination. Fall can be a bad time for fruit fly infestations and it can be explained in two words, “harvest season.” At the end of the summer, growers and gardeners are picking and processing the last of their fruits and vegetables. Farmers’ markets are overflowing with produce and most of us are bringing home everything from peaches to melons.

A Good Harvest Season Means Fruit Flies

Fruit flies have had all summer to build up their numbers with repeated generations since each fly generation only takes about a week. Fall harvest is their last, great hurrah. Part of the problem too is that, during harvest, excess or damaged produce is left on the ground or in storage to rot and provide a continuous supply of fruit flies until the first frost.

Fruit flies lay their eggs on the surface of overripe or fermenting foods (not just fruits). They are attracted to the yeasty smells that indicate fermentation, which is why you can’t enjoy a glass of beer or wine either. After feeding, the mature larvae leave their food source to pupate in a dry spot, and adult fruit flies emerge to start the process over again.

Here’s How Fruit Flies Get Inside

You end up with fruit flies in your home in two main ways: (1) the produce that you bring inside (whether from a market or your own garden) may be already infested with fruit fly eggs or larvae, or (2) fruit flies that are infesting produce outside your home are finding their way inside through windows or doors, or other openings (see Fruit Flies Can Come From Many Sources). If you can or process fruits, you are even more likely to attract fruit flies to your kitchen.

The problem is that once you have fruit flies in your home, they can also breed in other moist, decaying materials such as garbage spills, the liquid left in drink bottles or cans, and scummy drains (see Other Sources for Fruit Flies Besides Fruit).  One reason they are so difficult to control is that there may be multiple breeding sites in your home, so a thorough inspection is necessary.

You don’t have to put up with fruit flies. Give Colonial Pest a call. We can do a thorough inspection to identify breeding sites and can set up fruit fly traps to capture adult flies. If you have a garden or fruit trees in your yard, do yourself a favor and pick up any overripe, damaged, or rotting produce that is no doubt breeding fruit flies. Keep any ripe fruit or vegetables in the refrigerator until you get rid of the infestation.