Learn more about Flies

The house fly overwinters in either the larval or pupal stage under organic piles of debris or in other protected locations. Warm summer conditions are generally optimum for the development of the house fly, and it can complete its life cycle in as little as seven to ten days. As many as 10 to 12 generations may occur in one summer.

Each female fly can lay up to 500 eggs in several batches of about 75 to 150 eggs, each over a three to four day period. The number of eggs produced is a function of female size, which is principally a result of larval nutrition.

The legless larva or maggots emerge from the eggs in warm weather within eight to 20 hours, and immediately feed on and develop in the material where the eggs were laid. The full-grown maggots have a greasy, cream-colored appearance and are 8 to 12 mm long.

The house fly is 6 to 7 mm long, with the female usually larger than the male. The eyes are reddish and the mouth parts are sponging. The thorax bears four narrow black stripes, the abdomen is gray or yellowish with dark midline and irregular dark markings on the sides. The underside of the male is yellowish.

Helpful Facts:

• Adult flies feed on liquids containing sweet or decaying substances.
• Larvae feed on moist food rich in organic matter. Although they are attracted to a variety of food materials, house flies have mouth parts, which allow them to ingest only liquid materials. Solid materials are liquified by means of regurgitated saliva.
• Flies are inactive at night, with ceilings, beams and overhead wires within buildings, trees, and shrubs, various kinds of outdoor wires, and grasses reported to be their choice for resting sites.
• The more common control measures for the house fly are sanitation, use of traps, and insecticides. The use of biological control in fly management is still at a relatively early stage.
• Good sanitation is the basic step in all fly management. Food and materials on which the flies can lay their eggs must be removed, destroyed as a breeding medium, or isolated from the egg-laying adult. Since the house fly can complete its life cycle in as little as seven days, removal of wet manure from farm and ranch settings at least twice a week is necessary to break the breeding cycle. Wet straw should not be allowed to pile up in or near buildings. Since straw is one of the best fly breeding materials, it is not recommended as bedding. Spilled feed should not be allowed to accumulate but should be cleaned up two times a week.
• Elimination of breeding areas is necessary for good management. Garbage cans and dumpsters should have tight-fitting lids and be cleaned regularly.
• Fly traps may be useful in some fly control programs and work especially well in the home environment
• House flies are attracted to white surfaces and to baits that give off odors.
• Indoors, ultraviolet light traps will collect the flies inside an enclosure for easy disposal.