The House fly is the most common fly found inside homes and structures hence the name House fly. They’re not only a nuisance pest but they are important pests to control as they have been found to harbor and spread over 100 different pathogenic organisms and disease organisms. They range in size from 1/8″-1/4″ long as adults and are a bluish gray to black in color with four narrow black longitudinal stripes on top of the thorax (the part behind the head) when looking at it dorsally (from above).
The adult female will lay her eggs in clusters of about 20-50 for a total of 75-150 per batch laid. She can lay up to 5-6 batches in her lifetime which adds up to a lot of flies very quickly. The eggs are laid in areas of moist debris, hatch in about a day or two and the larva (maggots) will go through three instars over the course of about seven days. After maturing as a larva, they will then seek out a cool dry place to pupate. The pupal stage can last anywhere from three days up to four weeks to complete. Once emerged as an adult, they live another 15-30 days. They can go from egg to adult in as little as six days if the conditions are right. With their fast reproductive potential – it is most important to identify the breeding source or sources and remediate those sites in order to gain long-term control.
Interior breeding sites are not common unless it’s something like an interior trash room or compactor room. The majority of House fly problems stem from outside structures. Control can be achieved in many different ways such as Insect Light Traps (ILTs) that emit a certain UV light spectrum which attracts the fly to the trap and they become stuck on a glue board tray under the lamp or they become zapped by an electrical current. Glue ribbons hung from ceilings are another way to trap them. A professional pest control technician may employ a number of residual insecticides around entry points into the affected areas and also may use fly baits that the flies sponge up and it kills them. Mechanical means such as sealing of gaps around windows and doors, installing air curtains over doorways that are constantly open, and trapping the flies could be considered as well.