Although the fruit fly (also known as a small fly) has historically been considered a nuisance pest, recent research proves that small flies contaminate food with bacteria carried from unsanitary surfaces (such as trash, drains, mops, etc.). Small flies feed and breed in decaying and bacteria-ridden areas, then land on food and food-contact surfaces where they can transmit foodborne bacteria and ultimately spread different types of foodborne illness. Economic risk is a reality, as restaurants have been ordered by health departments to close due to fruit fly infestations. 

What starts as a small problem can quickly overrun your operation, since small flies lay up to 100 eggs per day and each egg matures into a fly in 10 to 20 days. Each species of small fly can indicate unique sanitation problems, said Ecolab Senior Scientist and Urban Entomologist Dr. John Barcay. “An infestation of fruit flies can signify issues such as over-ripe, rotting produce or dirty drains, while a phorid fly infestation is indicative of dirty drains, stagnant water, roof leaks or sub-slab sewer line breakage. Moth flies will result from sanitation issues in drains, filters, and sewers,” Barcay explained. “But,” he added, “no matter what species of fly you have in your facility, it is a food safety issue indicative of sanitation and/or structural issues, and could lead to audit or inspection failures as well as poor customer experiences that create a negative economic impact on your business.”