Where Do Fruit Flies Come From, Anyway?

Missy Henriksen - National Pest Management Association

One of my absolute favorite things about summer is the incredible fruit that’s part of the season.  Without question, I do my part in supporting those who grow tomatoes and nectarines. Those same fruits that bring me so much delight, however, became my nemesis last night.  I had hoped to get one more BLT out of the last locally grown tomato in the bowl and enjoy the last of a particularly good batch of nectarines but something beat me to the enjoyment of them – fruit flies! 

In recounting my disappointment to a friend, she asked the question that I so often hear, “where do those things come from anyway?” Like my kids when I am trying to stealthily enjoy a candy bar, or my dog when there’s cereal milk to be had, fruit flies seem to emerge from nowhere! Contrary to popular belief, they do not come from the interior of the decaying fruit and are not spontaneously “born” from the rottenness of fruit.  Rather, they detect the yeast produced by fermenting fruit from great distances. Once they have identified an intended target, they have little trouble getting to it as their tiny size allows them to enter a home through miniscule cracks and crevices.  Even most window screens won’t deter them.

Here are a few things you should know to keep fruit flies at bay so you won’t find yourself in the same predicament I have:

1)    If you keep fresh fruit on the counter, check it often for signs of over-ripening or decay.  Over-ripe fruit should be disposed of in a sealed trash can, outdoors.  A female fruit fly lays an average of 500 eggs on the surface of fermenting fruit. You don’t want those eggs hatching in your kitchen trash can!

2)    Run your garbage disposal regularly.  Fruit flies LOVE the decaying food matter that accumulates down the drain.

3)    Wash or replace mops and sponges regularly. They also LOVE the old food particles these cleaning items gather.

4)    Don’t keep dirty dishes around. Dirtied dishes gathered in your sink, particularly those with fruit remnants, and soiled dishes that sit for too long in an un-run dishwasher can also invite these flies.  

Fruit flies, like many pests, can be prevented by following good sanitation practices.  I know my children think I am just nagging when I remind them to put their dishes in the dishwasher but there really is a more important reason: pest prevention!   I don’t want any other deterrents to interfere with my next BLT.  Hear that girls?