How to Make a Homemade Fruit Fly Trap

Trapped Fruit Fly

Start with a 16 oz. or so water bottle with consistent ridges and valleys in the middle section. Cut the bottle in two along one of the valleys.

Then trim about one third of the rise from along the upper edge.

When you are done the two halves should snap together with a good fit and the bottle will be about a half inch shorter. It should be strong enough to survive a drop to the floor without opening however the seal won't be perfect and it will leak water.

Cut a circle of paper 3 to 4 inches in diameter. Then cut a wedge out of it. I used a coffee filter but you can use regular paper or newspaper. The idea was to allow maximum vapors to escape while still being a physical barrier.

Roll the paper into a cone. Mine overlapped about half way. The point does not have to be perfect, there can be a small hole. If yours ends up perfect then cut a hole about a sixteenth of an inch. The hole shouldn't be much bigger than that. You want a hole at the tip just big enough for them to go through.

Put the cone into the top of the bottle so that it extends well into the bottle.

Fold the paper down around the top of the bottle and seal with tape. Be sure it is well sealed. My first one had a small gap and after there were a couple dozen or so fruit flies in it they were coming out about as fast as they were going in.

Prime it with some banana peel, I used a fresh one and one a couple of days old, peach pit, or other fruit and some warm water and you are good to go.
Cider vinegar can also be used as an attractant. There are all kinds of recipes including such strange things as urine.
When you have caught a few you can take the bottle outside and release them.


Copyright Lee 2006