These nasty buggers multiply faster than gremlins, and the time to take care of it is when you see the first fruit fly (but who ever actually does that?).
All you need is a glass or jar, a large piece of paper, and some bait (i.e. Something sweet to attract them. I used a bit of fruit, but vinegar or wine will do the trick).
Make your paper into a cone shape above the bait and watch those dummies fly around unable to get out.
|Me -1, fruit flies-0|