NPIPM:Phoridae
Authors: Ashley Mueller, Buyung Hadi
Flies are one of the most recognizable pests in the home. While they can be a nuisance, some species are a cause for health concern. These medically important flies are capable of transmitting bacteria and other disease-producing organisms that can affect the human digestive system.
Flies undergo four developmental stages: egg, larval, pupal, and adult. Flies are attracted to decaying organic materials. Places in the home where they are likely to reside are near room-temperature ripened produce and seldom-used drains and sinks. Adult flies are primarily active during the day, so they are often noticed. Preventing and managing flies indoors requires proper food storage and good sanitation practices in the kitchen and regular cleaning of areas that could be optimal breeding sites.
Identification
Adult phorid flies (various species) are about 1/8 inch long. They are also called “humpback flies” because their thorax is humpback-shaped. The most common characteristic of this fly is behavioral. When disturbed, rather than flying, the phorid fly will scurry across a surface to escape danger. Because of this behavior, they are sometimes called “scuttle flies.” Most other flies immediately take flight to avoid danger.
Habitat
Phorid flies can be found in a variety of habitats indoors and outdoors, most often on or near decaying vegetation. Some species of these flies have been known to live in the nests of ants and termites and have shown parasitic behavior towards other insects.
Life Cycle and Seasonal History
Breeding sites of phorid flies can be diverse, and they can range from drains to trash cans to aging fruits. Adult females lay eggs beneath the surface of decaying organic matter. In two to three days, the eggs hatch, and the larvae are nearly transparent in appearance. As they mature, they become whitish and reach a length of 4.5 mm. The pupal stage follows, and initially the pupae are white, then they turn dark yellow-brown. After about 20 days, adults emerge. Adult phorid flies may live approximately one week. The length of the generation does vary with temperature.
Adult phorid flies are most common in the late summer and early fall months. These flies are usually attracted to light, and they can be found near windows and doors to houses and greenhouses.
Human Interaction and Urban Impact
Phorid flies do not bite. However, because phorid flies breed on decaying organic matter, they have the potential to cause health concern. They are capable of transferring bacteria from one surface to another, which is especially important in hospitals, restaurants, and schools.
Prevention and Management Approaches
Identifying and eliminating breeding sites are important steps in controlling phorid flies. Drains should be cleaned regularly to prevent phorid flies from choosing them as breeding sites. Maintaining good sanitation practices is important. Sites of food preparation should be kept clean, and trash cans into which food is dumped should be taken out on a regular basis. Inspecting food items, especially fruits and vegetables, before bringing them into the home is another prevention method. If adults are found in the home, they can be removed using a vacuum cleaner.
Chemical methods may be necessary if multiple breeding sites are found in the home. Aerosols containing pyrethin can be used to target cracks and crevices where breeding may take place. The use of DF 5000 gel, a selective bacteria complex, may also be warranted. This product is not sold to the customer market; it is only available to pest control operators and hospital, restaurant, and food service personnel. Always use precaution and follow the label carefully before using any insecticide. Insecticides have a certain amount of toxicity to mammals; children and pets are especially at risk.
Other Online Resources
For information regarding labels of chemical control options, please visit NPIC MAPL
