Flesh-eating screwworms cause worry. When they were detected in Florida

New World screwworms, parasites that feed on warm-blooded animals' tissue, are drawing concern as USDA data show detections about 25 miles from the U.S. border in Coahuila, Mexico, south of Texas. The species has not been found in the United States as of June 4, and Florida experienced a small outbreak in 2016. Eradication relies on releasing sterilized male flies to prevent reproduction; females typically mate only once, which collapses populations without chemical pesticides. The USDA says the approach is safe and environmentally friendly, and does not pose a risk to other animals.