Attribution: Adam Chamness, (macro) [CC-BY-SA-2.0], via Wikimedia Commons
Small flies 1/8-inch in length
Tan brown with red eyes; wings fold flat over body
Fruit flies are common in homes and commercial facilities where food is prepared and served. These flies are usually carried in on fruits and vegetables. The larvae feed on yeasts that develop within ripening/decaying fruits and decaying organic matter. They are also known as pomace flies or vinegar flies because they are common pests in facilities producing vinegar. Because these flies frequent unsanitary conditions, they are a potential health concern when they occur in food facilities and hospitals.
Any freshly decaying, moist organic matter that sits undisturbed for five or more days. Usually associated with fresh fruits and vegetables stored at room temperatures. Once inside, adult flies emerging from a piece of infested fruit can find and exploit other potential breeding sites such as poorly maintained trash containers, recycling bins, food kicked underneath tables, coolers, etc., and garbage disposals. They also may be found breeding in dumpsters outside and flying to and entering the building through doorways. The breeding media must be continually moist for the larvae to develop and generally in a fairly fresh state of decay. Any crack or area where organic matter can accumulate can support these flies.
The key to controlling fruit flies is finding the breeding sites and removing them by proper cleaning practices. Fruit flies, like other types of small flies, can be difficult to totally eliminate because they can breed in such small amounts of organic matter. A number of breeding sites can be found and eliminated while others may easily be overlooked. The inspection needs to focus on finding all sites where moist organic matter has accumulated and then removing that matter completely. Often, in homes, fruit flies are carried in on bananas and when the bananas are removed, the presence of flies disappears within a few days.