Saturday, September 14, 2013

Build a better fruit fly trap

Three years ago I posted about fruit fly traps.  Not wanting to use a canning jar or drinking glass for mass murder, I've taken to using whatever glass container destined for the recycling bin happens to be at hand.

But lately we've been overrun - overflown? - with the little buggers.  We have no fruit sitting out, no appealing garbage, no houseplants, a clear garbage disposal. 

I think I finally figured out their breeding ground: the grape arbor next door is heavy with purple fruit right now.  When I let out the chickens this morning, I was besieged by fruit flies.  Ugh. 

They are truly everywhere.  Kamikaze dive-bombing into my wine, annoying Gene to the point that he keeps a fan on him when he's working at his computer, getting their sexy on in pairs on the walls of the kitchen.

We were desperate to get rid of them.  The weather is getting cooler but we still have a lot of these annoyances in the house.

I decided to try an experiment.  I made up a large batch of the fruit fly attractant - apple cider vinegar, water, and dish soap - and poured it into 3 different containers.  I put the containers in the windowsill and left them for 2 days.  The fruit flies were already starting to drown by the time I had put the containers down.

From left, the containers are:
  1. Mike's Hard Lemonade bottle
  2. Safeway preserves jar (To keep my canning cred,I must point out that I did not buy this!)
  3. Wide-mouth pint jar with holes poked in the lid
Two days later I estimate that the traps killed well over 200 flies.  The number of fruit flies in our kitchen has decreased dramatically.

With the lowest kill rate was the Safeway preserves jar.  I counted about 30 fruit flies in the jar after 2 days.  I'd had this jar out on the sill all summer, which probably explains why we have such a problem with fruit flies this year: the trap wasn't working well!

With a moderate success was the long-neck bottle.  I didn't count the flies but there were about 50-70 in there by day 2.  I suspect that the flies would enter the bottle and have a hard time getting out again.

The wide-mouth jar had the best results by far.  I watched countless flies enter the holes in the lid, touch the liquid's surface, and immediately sink.  I estimate there are well over 100 dead fruit flies.

It's always shocking how many fruit flies one of these traps will catch. 

My lesson here is that as much as the attractant in your fruit fly trap matters, so does the shape of the container.  If your trap isn't working like you think it should, try a different container.


  1. Thank you so much for this! We've been having fruit fly issues, as well. Will give the wide mouth jar a shot.