Common Flies and Fly Control

Drain flies and Fruit Flies

These flies are often mistaken for each other, but they are two different species.

Drain flies (often called "moth flies" due to their fuzzy, moth-like appearance) often seem to mysteriously appear out of nowhere. In reality, however, drain flies breed in sewers, septic tanks, sewage treatment plants, and drains. Adult drain flies may become so numerous indoors that they congregate at windows, darken lamp shades at night, fall into food and accumulate around showers, bathtubs, sinks and floor drains, especially in basement or other areas with faulty plumbing or where the water has evaporated from the drain traps.

Fruit flies tend to congregate around rotting or ripened fruit or other decaying vegetable matter. They often are found in kitchens, places where fruit or vegetables are stored, and around taverns and other areas where food and drinks are served. They can be readily distinguished from other small flies by their bright red eyes.

House Flies

House flies are important public health pests throughout the world because of their filthy habits and their ability to vector microorganisms and parasites that cause serious diseases such as chronic diarrhea, cholera, food poisoning, dysentery, yaws, conjunctivitis, and many, many others.

Because they react to movement at least five times as quickly as humans do, they can be very difficult to swat. Control is accomplished through a combination of sanitation, trapping, and (if needed) chemical control.

Cluster Flies

The cluster fly is slightly larger than the common house fly. There are no distinct lines or stripes behind the head, and the abdomen has irregular light and dark gray areas.

Cluster flies are actually the adult stage of an earthworm parasite. Females lay their eggs outside in the the soil, and the larvae feed by parasitizing earthworms. After a few weeks, the larvae pupate into adults, who feed primarily on the nectar of flowers.

When fall approaches, adult cluster flies seek harborage in protected areas, such as in exterior cracks and crevices of buildings (around windows and doors, under clapboards, etc). They try to work their way into a building as much as possible to take advantage of warmth radiating from the building. For best results, treatment should occur in the mid to late summer, before the flies have begun to enter the building.