Mid-Missouri Pest Information: Flies

House flies are a dull gray with four black stripes down their backs. They are the most common fly found in american homes and restaurants. The house fly is widely distributed and can transmit serious diseases such as typhoid, cholera, salmonella, dysentery, tuberculosis, and anthrax. During the day, house flies tend to rest less than five feet from the ground on walls, floors, and on random items. At night, house flies will change their preference and rest above five feet from the ground on ceilings, light fixtures, dangling light cords, tall plants, etc. The house fly can only eat liquid food, so they spit saliva on food to pre-digest it, then suck the food back up.

Blow flies are partly or wholly metallic blue, green, or brassy in color. They are sometimes black as well. Blow flies, also known as bottle flies, are just as bad if not worse about transmitting disease than the house fly; typhoid, cholera, Salmonella, dysentery, tuberculosis, and anthrax are just a few of the diseases they flies can transmit. Blow flies live and breed in dead rotting flesh, but if not available, they will feed on animal excrement, decaying vegetation, or garbage. Dead rodents, birds or any other small animal can cause an infestation of these flies inside homes and structures. Blow flies are always the first one on the scene when an animal or human dies. A lot of times, the larvae of the Blow/Bottle fly is used in forensics to determine time of death in a murder case. Though nasty, they can be quite a beneficial insect!

The cluster fly has no distinctive marks or striping. The name reflects this species’ habit of forming compact clusters of hibernating individuals, typically in wall voids, soffits and attics. As days get shorter and the weather starts cooling down in the fall, cluster flies will start their migration back to structures and homes to begin their winter hibernations. One of the signs of this migration is on the south side of the structure or home, they will begin to cluster on siding and brick walls to stay warm, and typically the south side of the structure will be the warmest side. Cluster flies will enter any crack or crevice of a structure to hibernate in. On sunny winter days, cluster flies will become active and enter the inside by squeezing in and around light switch covers, outlet covers, light fixtures, exhaust fans, attic fans, etc. Once inside, cluster flies are attracted to light coming in through windows.

Most of the time, this small fly is easily identified by its red eyes. The fruit fly’s body is tan in the front and black on the rear. They are drawn to ripened or fermenting fruit and vegetables, and they breed in drains, garbage disposals, trash cans, mops, rags, etc. They are mainly considered a mere nuisance, but can sometimes contaminate food with bacteria. Sanitation is the best defense against developing a fruit fly problem. Discarding over-ripened fruit and vegetables will also help in prevention.

These tiny flies are usually black, brown, or yellowish and have wings that may have dark patterns on them. Adults are found on or near decaying organic matter, where they lay their eggs and the larvae mature. When gnats are found indoors, it is almost always the result of over-watering plants. Water leaks, moisture problems, or feces in bird cages can result in a gnat problem. The elimination of breeding sources is the most important step in preventing a gnat problem.

These flies have a furry body and wings. Their colors can vary from yellowish to brownish-gray to black, depending on the species. They have segmented antennae that have long hairs on them and their wings are held roof-like over their body when they are at rest. Because of their small size, drain flies, also known as sewage flies, are able to penetrate ordinary screens. They are weak fliers and are usually crawling on walls and other surfaces when found indoors. When they do fly, it is usually just a few feet at a time! Drain flies breed in sewage, but apparently do not transmit human disease. They may be found hovering above drains, dirty garbage cans, bird baths, clogged gutters, storm drains, moist compost, rain barrels, septic tanks, etc. In minor cases, simply cleaning the drains with very hot water will take care of the problem. In more severe cases, using a stiff brush to clean the inside of the drain will be required to eliminate the slimy film they reproduce in.