Houseflies are one of the most common pests in the US. Surveillance techniques include identification of the larval or adult stage of the fly, its food source and potential breeding sites.
The life cycle of the fly starts with the egg and larval stage. These two stages develop in animal and vegetable refuse. In favorable conditions, eggs can hatch in as little as 24 hours. Fly larvae (maggots) are a creamy-white color and are about 1/2 inch long. This stage lasts for 4-7 days and the shell hardens and darkens. This marks the beginning of the pupal stage. When the pupal stage is complete, the adult fly exits the puparium, dries, hardens, and flies away to feed, with mating occurring soon after emergence. Adult flies are dull gray and approximately 1/4 inch long with four dark stripes on the middle section of its body. Houseflies breed in decaying organic material such as manure or composting piles.