The male spotted wing drosophila, left, has the distinguishing brown spots on its wings. Credit: Courtesy of Griffin Dill

This story was originally published in September 2021.

It would be tempting to think that with the cooler temperatures that come with autumn in Maine, there would be relief from pesky insects. But that would be wrong. Sure, you may no longer be annoyed by seasonal bugs outside, but inside could be a different story.

Here are three of the more common tiny insects that might be buzzing around inside your house and a few things you can do about them.

Fruit flies

The common fruit fly, also known as vinegar flies, are attracted to overripe fruits in addition to yeast and cider-heavy products. This time of year, when there are lots of fruits in season in Maine the state’s fruit fly population spikes.

This is the time of year when people want to go apple picking and stock up on other end of the season produce like tomatoes and root crops. But storing that bounty on your kitchen counter can be a mistake. The flies get into your home hitchhiking on that fruit or through an open door or window if they detect overripe fruit.

The best way to keep fruit flies from taking over is to store your produce in the refrigerator or covered with plastic. You should also make sure your indoor trash is covered.

To get rid of existing fruit flies here are some ways to deal with them.

Spotted wing drosophila

The spotted wing drosophila is another kind of fruit fly that can make your indoor life miserable, in addition to having a major impact on any late season berry crops in your garden. Unlike the common fruit fly which is a simple nuisance, the spotted wing can destroy ripening berry crops.

The female spotted wing drosophila uses a sawlike structure on her body to cut into the ripening fruit. She then lays her eggs in this cavity. Once the eggs hatch the larvae start eating the berries, rendering them into mushy mess.

If the hatch happens to take place soon after the berries are picked, you can have a nasty surprise when your recently harvested or purchased berries turn to mush on your kitchen counter and there are larvae crawling out of them.

The best defense against the spotted wing drosophila is picking fruit a little earlier in the ripening process than normal. Once picked the berries should immediately be refrigerated to at least 34-degrees Fahrenheit to halt the development of any eggs or larvae.

Cluster flies

Larger than fruit flies, cluster flies can be a major indoor annoyance. Cluster flies, also known as attic flies, resemble the common house fly, a dark grey or black fly that’s a little under a quarter of an inch long. Cluster flies are larger with yellowish hairs on the body. Their name comes from their behavior of amassing or “clustering” for warmth out of sight behind household siding, shingles or other cracks and crevices in attics, lofts or other wall voids.

Around the time Maine gets its first hard frosts, the cluster flies start gathering on sunny sides of houses. As temperatures cool, they sneak into any cracks or crevices they can to get inside.

Dormant while it’s cool inside, they will become active on warm days or if the heat gets turned up in a room.

The best defense is to keep them from getting inside in the first place. Seal up cracks and place screens over attic vents and soffits. Large indoor gatherings of cluster flies can be vacuumed up and released outside. You can also use commercial products like insect strips or sprays.

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Julia Bayly

Julia Bayly is a reporter at the Bangor Daily News with a regular bi-weekly column. Julia has been a freelance travel writer/photographer since 2000.