Cochliomyia is a genus in the family Calliphoridae, known as blowflies, in the order Diptera. Cochliomyia are commonly referred to as the New World screwworm fly. There are four species in this genus: Cochliomyia macellaria, Cochliomyia hominivorax, Cochliomyia aldrichi, and Cochliomyia minima. The two main species are Cochliomyia hominivorax and Cochliomyia macellaria.Cochliomyia hominivorax are known as the primary screwworm because their larvae produce myiasis and feed on living tissue. This feeding causes deep, pocket-like lesions in the skin, which can be very damaging to the animal host. Cochliomyia macellaria are known as the secondary screwworm because their larvae produce myiasis, but feed only on necrotic tissue. This species is forensically important because it is often associated with dead bodies and carcasses. Both C. hominivorax and C. macellaria thrive in warm, tropical areas.