A New World screwworm has been confirmed in a calf in Texas — the return of a flesh-eating fly that U.S. agriculture officials wiped out domestically back in the 1960s. The detection has put the cattle industry on alert.
The screwworm isn’t a typical pest. Its larvae burrow into living tissue, feeding on flesh from the inside. Left untreated, an infestation can kill an animal. The fly was eradicated from the United States through a decades-long sterile insect program that ended domestic cases by the mid-1960s. Finding one now in a Texas calf raises questions about how far the pest may have spread.
Texas sits at the center of U.S. beef production, and any reestablishment of the screwworm there would be a serious problem for ranchers across the country. Utah’s cattle operations – spread across the state’s rangelands from Cache County to San Juan County — would face the same exposure if the fly moves north along livestock trade routes.
NPR reported the confirmation Thursday, June 5, 2026, but details on how the calf was identified, which part of Texas was affected, and whether additional cases have been found weren’t immediately available. Federal agriculture officials have not publicly confirmed whether a broader investigation is underway.
Reported by NPR. Read the original report.
