Case Studies

Cowleys Pest Services Case Studies: Fruit flies all over this Asbury Park, NJ kitchen.

Monday, January 21st, 2019 by Bill Cowley


Recently, I was sent to one of our commercial customers in Asbury Park, NJ. We were contacted because of an infestation of fruit flies around the drain in the commercial kitchen. Upon arrival, I immediately went to the area where the flies were concentrated. It did not take long for my inspection to observe a significant build-up of food residue inside the drain, which provided the gnats with a perfect breeding ground. These flies will lay their eggs in any moist organic material, and they are especially attracted to ripened or fermenting fruits and vegetables. And they reproduce quickly — a fruit fly goes from egg to adult in about one week. 


Often, you’ll see fruit flies hovering around overripe unrefrigerated products, especially bananas, potatoes, and onions. As food decomposes, it releases certain smells from the  bacteria and fungi eating away at the food, and the smells attract fruit flies and other insects. But it’s not just visible foods that are the problem. Like the situation I found here, fruit flies can become a problem when they find a food source in hidden locations. In restaurants and other food-related businesses, fruit flies often become a problem when organic matter is allowed to collect inside drains, underneath appliances, and in garbage cans that have rarely, if ever, been cleaned.

To resolve a fruit fly infestation, it is important to locate and eliminate the organic breeding material that’s causing the problem in the first place. If there are adult fruit flies hovering about on your premises, there are fruit fly larvae eating and developing nearby in some decaying organic matter, which in this case, was hidden in the drain. The build-up here was so extensive in the drain, I was surprised that it wasn’t clogged up completely. I started by using a scraper, like a dental hygienist scraping off tooth plaque, to get as much of the gunk that I could rate out of the drain. After I manually cleaned out as much as I could, with the scraper, I continued to work on the residue with a scrubbing brush and Bio-foam, a bioenzymatic cleaner. With the larvae killed, the last generation of the adult flies will soon die off and the area will be free of these gnats.  

Removing the breeding habitat will resolve the current infestation. However, the flies will likely return if the underlying problem is not resolved. I discussed the sanitation problem and built-up food reside in the drain with the manager and the importance of removing attractants to prevent fruit flies and other pest infestations. I was assured that, going forward, the drain would be regularly cleaned and the staff would be made more aware of the importance of following sanitation protocols to minimize food residue throughout the kitchen.