On Jun. 3, 2026, an infestation ​of the flesh-eating screwworm parasite may have been detected in South Texas, and a sample is at ‌a federal government laboratory for testing, the U.S. Department of Agriculture said.

Samples from two calves on a cattle ranch in La Pryor, Texas, were taken on Tuesday and sent to a federal lab in Iowa, Texas Representative Don McLaughlin told Reuters earlier, adding he had seen ​photos and videos of the animals.

New World screwworms are larvae or maggots of the NWS fly (Cochliomyia hominivorax), that cause a painful condition known as NWS myiasis. NWS flies lay eggs in open wounds or orifices of live tissue such as nostrils, eyes or mouth. These eggs hatch into dangerous parasitic larvae, and the maggots burrow or screw into flesh with sharp mouth hooks. Wounds can become larger, and an infestation can often cause serious, deadly damage or death to the infected animal.