The tiny fruit fly is one of the most common flies found in homes. It is often brought indoors on fresh fruits and vegetables, and it sticks around because it can find plenty of food in homes. Fruit flies are 1/10 inch to 1/5 inch long, and they have red eyes, yellow-brown bodies, and black rings around their abdomens. They belong to the Drosophila genus and also go by the common names of vinegar flies, pomace flies, and wine flies.
As their name suggests, fruit flies feed on overripe fruits, rotting vegetables, and other foods they find in the garbage or even in drains. And as their other common names imply, they also feed on wine, vinegar, and pomace (the pulpy residue left from the crushing of fruits). Moreover, because fruit flies like the yeast in foods, they are often attracted to breads and other baked goods. Fruit fly populations usually explode in the late summer and fall because that's when many fruits are ripe and being harvested. The average fruit fly lives around 50 days, and the female fruit flies can lay hundreds of eggs during their lifespan.
Fruit Flies in the Home
The fruit fly is not necessarily capable of causing damage to a home. It is just a great nuisance, especially when there are a lot of them.
However, fruit flies can damage harvested produce because they can carry and spread organisms that cause rot. This fly can be of particular concern in the harvesting of strawberries that are picked for freezing. In this situation, the fruit is left on the plants to fully ripen. And as it ripens it becomes attractive to fruit flies, thus making the fruit particularly susceptible to the rot-causing organisms. The same is true for vineyards, where the grapes are left on the vines to ripen.
Thus, if you have a home garden or leave ripe fruit out in the open, you're at risk for attracting fruit flies and might lose some of your produce because of them. But the key to prevention and control is simple: sanitation.
How to Control Fruit Fly Infestations
As with most flying insects, control of a fruit fly infestation is best achieved by limiting the flies' ability to feed and breed. This involves:
- Refrigerating or discarding ripening fruits
- Cleaning any spilled juices, sodas, wines, or other liquids
- Washing beverage containers before recycling them
- Regularly cleaning trash containers and the areas around them
Once you have sanitation under control, often the best approach is to wait for the fruit fly population to diminish. Particularly for outdoor infestations, such as around trash containers, the arrival of cold weather can cause a fruit fly population to disappear as rapidly as it seemed to grow in the warm weather. But regardless of where the infestation is, if the flies have no food, they likely won't be a problem for long.
Furthermore, there are pesticides that can work on serious fruit fly infestations, though it's best to try to naturally control the infestation first through sanitation before turning to chemical methods. A household pyrethrin aerosol insecticide will kill the adult flies, but it will not kill the larvae. For that reason, repeated application is typically necessary. When using any pesticide, always read and follow all label directions.