Fruit flies (Drosophila melanogaster)1, although essential tools in the study of molecular genetics, are really annoying in the kitchen! They like to lay their eggs on old produce and go from egg to adult in 1 week. That means that as long as you eat your produce in less than 1 week, you won't have a significant fruit fly problem. However, no matter how careful you are, at some point everyone brings home some peaches or plums containing fruit flies. You may have read about other fruit fly trapping methods which involve keeping a dish of apple cider vinegar with a few drops of dish soap in it near your fruit bowl. This is a great way to catch a few fruit flies every day for the rest of your life. There are also homemade traps that require you to go out and buy a funnel. Here is a simple trap made from items you most likely already have that will get rid of all of your fruit flies in 1 day.
First of all, shoo away the fruit flies from your fruit bowl and move it to a different location in your kitchen (preferably at least 5 feet from its original location.) Discard any old produce and wash the fruit bowl/stand. If you have a severe fruit fly problem, you might want to move the fruit to a different room and put as much as possible in the fridge.
Ziplock bag fruit fly trap
1. Get a gallon sized zippered bag (must have the zipper).
2. Put a partially peeled old banana in the bag (or some other produce that the fruit flies would love or a partially empty yogurt cup).
3. Use a drinking straw to prop the bag open.
4. Set the trap in the same spot on the countertop where the fruit bowl used to be.
5. Let it sit there undisturbed for a few hours (3-4 hours).
6. After a few hours, quietly sneak up and quickly ZIP THE BAG. You will most likely have caught a dozen or so fruit flies.
7. Throw this bag away in the OUTSIDE trash can. I know many people wash their plastic bags, dry them on cool drying racks like this, and reuse them.
However, this might be one time that you just want to throw the bag away.
8. Continue setting traps until all of your fruit flies are gone. It will most likely only take 1 or 2 traps and less than 1 day.
9. After the coast has been clear for 24 hours, you can move your fruit bowl back to its original location.