Screwworms (Diptera, Calliphoridae, Cochliomyia hominivorax [Coquerell] are important obligate parasites of various terrestrial mammals, including man. Distribution is restricted during winter months to tropical and subtropical areas of North and South America; but during other periods, the screwworm fly may disperse 500 miles or more from its normal overwintering area.
When held at 80 F (27 C), the adult flies mate at 2 to 3 days of age, and at 7 days of age, females oviposit shingle-like masses of 200 to 500 eggs. After an incubation period of 16 hours, larvae emerge and immediately start feeding in compact pockets, consuming primarily live flesh and wound fluids. In four to nine days after hatching, the larvae attain a body weight of 70 to 120 mg, drop from the wound, and burrow into the soil to pupate; adults emerge from the soil within eight days.
Although the screwworm
Baumhover AH. Eradication of the Screwworm FlyAn Agent of Myiasis. JAMA. 1966;196(3):240-248. doi:10.1001/jama.1966.03100160090027