Ah … summertime. The pinnacle of the produce season means amazing things for your palate: sun-ripened fruit, homegrown vegetables, and fresh herbs for days.
Unfortunately, ripe produce also invites other guests to the flavor party: fruit flies. These little monsters (drosophilidae), with their big red eyes and kneejerk-wave inspiring flight patterns, aren’t terribly harmful (they have a lifecycle of around ten days)…they’re just really, really annoying. They tend to dig on ripe (or overripe) fruit, stale water, uncovered trashcans, etc.
But, even the cleanest homes can fall victim, especially those who buy organic-method or local farm raised produce, or have their own gardens and fruit trees. But, no worries, you can solve your fruit fly problem overnight, with about a minute of work and this DIY fruit fly trap.
- One medium sized jar with lid – or – one drinking glass/bowl and some plastic wrap
- Hammer and nail
- 1/2 cup beer
Why do you need a fruit fly trap?
While fruit flies aren’t particularly harmful, they are super annoying. Where do fruit flies come from? If you think they come from inside your fruit, you’re mistaken. Fruit flies lay their eggs on moist surfaces, so nearly-ripe fruit is a perfect breeding group for their offspring. A fruit fly trap is the best way to keep these pesky insects from reproducing.
Is a fruit fly the same as a gnat?
Although both of these insects are in the same family, they’re not the same species. Fruit flies are more likely to be found indoors, where they feed on fruits and vegetables. Gnats, on the other hand, are usually found outdoors, where they rotting organic matter and fungal growth.
1) Get A Jar or Glass Container for your Fruit Fly Trap
Since we wanted to use and reuse our trap all summer, we opted for a Mason jar. If you don’t keep any on hand, any food jar will do, or you can use a drinking glass, and a piece of plastic wrap as the lid.
2) Make Some Holes
Punch a series of holes in the lid using nail or awl. Make them big enough to allow the fly in, but not so big that it will be easy for them to escape.
3) Fill It With Beer Or Juice
Fill the container with about a half cup of beer, or to whatever fills the container halfway. If you’d rather not use beer, try using a fruit juice or apple cider vinegar flies love.
Update: Adding a single drop of dishwashing liquid breaks the surface tension on the liquid, resulting in an immediate drown and no swarming around inside the trap. (Thanks, Mo!)
4) Place It Near The Flies
Screw on the lid, then take to the place where they flies are a-hovering…your fruit bowl, pantry, etc. Move any other sweet smelling things to a different location (like the refrigerator), making sure no fruit flies have hitched a ride.
Overnight, the flies will smell the beer (or juice/vinegar), and eventually fly in to the fruit fly trap. They’ll hover around above the liquid, eventually falling in and drowning. Every few days, pour out the flies and some of the liquid, and add more to give it a fresh aroma. Repeat as necessary.
Update: it turns out that apple cider vinegar is actually a better liquid to use for this type of trap (it smells stronger and lasts longer than the beer … not to mention you don’t have to waster perfectly good beer on fruit flies). Another fruit fly trap design involves using a paper cone to funnel the critters down into the liquid.
You’ll need a
- A glass (I’m actually using an old pasta sauce jar)
- A piece of paper.
- Some slightly icky fruit or some apple juice to lure the unsuspecting little rotters
The picture is fairly self explanatory, you just roll the paper up, tape it and jam it up in top there. (I’ve taped mine down too).
But actually I reckon if you used fruit enough you could probably make the trap non-fatal. I was once in a Buddhist temple in japan, it was late September and the mosquitoes were enough to incite craziness. The monks told us NOT to swat them, we could shoo them if we must, but it would be better to let them have a meal then go on their way. I am not a very good Buddhist.
I just stopped at the local hardware store for a project, and saw a commercial fruit fly trap under the trademark name “Terro.” With a retail price of near $10, I was determined to figure out what the liquid was in the small 1/2 ounce vile that came with the physical plastic trap; looks like a small apple. As soon as I poured the red liquid into the trap, I smelled the liquid. APPLE CIDER VINEGAR! Then I found this site, and it was confirmed. Seems that a commercial manufacturer would use the most effective and safe product, (liability issues, right?). So now, I’ll start manufacturing similar traps around our house. Thanks to all the contributors for the additional input. best from Al in SoCal.
after doing some resesarch, i decided on filling a mason jar with regular vinegar, a splash of dishwashing soap, and a slice of ripe banana. Before I could even get the cling wrap out of the cupboard, the fruit flies were already swarming! It seems to me that as long as there’s only one tempting thing in the room (you’ve cleared any fruit off the counters, taken out the trash, etc) anything fruity or fermented will attract them….you just need to find a way to make them stuck there! thanks for the tips!
I had those meal moths. I didn’t know it because they were in a cabinet I hardly ever went into. They got bad, and then the brown widow spiders set up shop to eat them. It was not fun trying to get rid of those, let me tell you! From now on, all grain stays in the freezer.