It's quite common for me to get a lot of fruit fly questions during the warm weather months, when these annoying little gnats are most active. One particular commercial client of mine in Edison, NJ was having an issue with fruit flies around his bar. He asked me if I could come in early one morning to perform an inspection in order to figure out where they were coming from.
More often than not, it’s a simple solution once you take into account fruit fly biology and their predictable behavior. When I walked behind the bar, I observed a few garbage cans that did not have bags in them. I instinctively knew this meant trouble, and once I looked inside, my suspicions were confirmed. The bottom of the cans had standing water and a large number of fruit flies congregating throughout the trash as though they were having their own private happy hour!
Fruit flies, just like mosquitoes and many other flying insects, are attracted to standing water. It's the key to life and their reproductive process. Where there is standing stagnant water, a wide variety of flying insects will lay eggs and start making a home. I took several pictures as well as a short video to show the client my findings.
The best way to resolve this fruit fly problem was to eliminate their breeding ground. The bar owner needed to take all of the trash cans outside and thoroughly wash them every night when the bar closes. Also, I suggested that he leave the trash cans outside at night. There was no need for them to be sitting behind the bar while the establishment was closed. Also, with these little flies, you can use air currents against them. Setting up a small desk fan and pointing it in the direction of where the fruit flies are congregating will create a headwind barrier that will prevent them from being able to land. The weight of a fruit fly is so minuscule that the airflow will keep them from flying toward the trash cans, preventing them from laying more eggs and increasing the population.
When I went back for the follow up three days later, all of the fruit flies were gone and the client was extremely happy that such a vexing problem for him could be solved so easily. Not every pest control problem requires chemical applications. Often, an understanding about insect behavior and how to go about creating an inhospitable environment for the bugs is more than enough to solve the problem. As the saying goes, a little knowledge can go a long way.