Fruit fly trap

A few folks I work with buy those huge jars of pretzels for all in the cube fields to enjoy. These plastic jars have nice wide mouths. A few months back, the building had a fruit fly problem. A little googling lead me to various trap designs from bowls, ziplock bags, glass jars and even your oven.

I settled on the funnel method and recycled one of the pretzel jars. Here is how you do it:

1. Clean the salt out of the jar
2. Cut a hole in the lid almost all the way to the edge
3. Cut a half-circle out of a piece of paper with a radius equal to slightly larger (1/8") than the diameter of the hole in the lid
4. Cut out a small semi-circle (quarter-sized) at the center to make the small opening for the funnel
   
5. Form a funnel, the wide opening should just be larger than the hole in the lid
6. Tape the funnel to hold it securely
   
7. Hot glue the funnel inverted in the lid making sure it is completely sealed
8. Put some fruit (banana, etc.) in and screw the lid on (I used a Styrofoam tray to put the banana on to keep the jar from getting nasty.)
9. Set the jar out.
   
10. Enjoy the satisfying feeling that you are getting rid of a pest.

Closeup of the installed funnel.


Closeup of the funnel hot glued into the lid.


Here is my trap.

I made the sign to stave off questions about what the thing is. The font is used as a warning to the flies. It worked beautifully, though building services took care of the bug problem a couple days after my trap was put up. But now I am ready for the next infestation.