““Scientists eradicated the screwworm fly from the United States in the 1950s. Capitalizing on the fact that the female screwworm fly mates only once, scientists released millions of sterile male flies in areas where the screwworm fly was a problem. This made sterile males far outnumber normal males, so female flies usually mated with the sterile ones and produced eggs that didn’t hatch. Several years of this sterile breeding eliminated the screwworm fly from the United States, but it still lives in South and Central America and occasionally travels into the United States with cattle imported from these areas. Wounds left by husbandry practices, such as branding, dehorning, and castration, expose animals to the screwworm fly.Therefore, these procedures should be done during the winter or dry season, when the number of screwworm flies is lowest14 Clinical Parasitology””
