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

New World screwworms are not yet in the United States, but the threat has moved closer after detections about 25 miles from the border in Coahuila, Mexico. The USDA notes these larvae feed on warm‑blooded animals and can invade wounds and body orifices, raising concerns for cattle health and potential spread to Florida, which faced a small Keys outbreak in 2016 that was eradicated by 2017. As of June 4, there were no indigenous U.S. screwworms, though the insect’s proximity prompts continued monitoring.

The screwworm’s life cycle involves female flies laying eggs in wounds; larvae then hatch and feed on living tissue. Eradication relies on sterilizing male flies with radiation and dispersing them to prevent reproduction, a method the USDA says is safe and environmentally friendly, with new sterile fly production and dispersal facilities being brought to support ongoing efforts.