Skip to content

New World screw worm detected in South Texas

scienceJun 4, 2026611,655

State and federal agriculture officials confirmed the New World screw worm, Cochliomyia hominivorax, in a calf in South Texas, the first U.S. detection since the species was declared eradicated in 1966. The screw worm fly lays eggs in open wounds and its larvae feed on living tissue, causing myiasis that can kill untreated animals and devastate herds. The species was eliminated in the 1960s through a decades-long sterile insect program that releases sterilized male flies to stop breeding. Containment now focuses on treating affected animals, quarantines, and renewing sterile-fly releases because rapid action is essential to prevent major economic losses for Texas ranchers and regional cattle markets.

1 source