A ‘fly factory’ whose product is living flies — 300 million of them every week — is to be built in southern Mexico to help eradicate screwworms, a major livestock pest.… They feed on living host animals through open wounds or sores. The fly factory will raise millions of screwworm flies, sterilize them with radiation, and release them from low-flying aircraft to mate with native flies, producing eggs that will not hatch.
Mexico and the United States joined forces to finally purge North America of the screwworm scourge. The fly factory opened in 1976 and legions of sterilized screwworm flies were released in both countries, including along Mexico’s Isthmus of Tehuantepec to obstruct northerly incursions. The eradication program was so successful that it spread to Panama.