Key facts
- A calf in La Pryor, Texas, tested positive for New World screwworm, the first U.S. case in decades.
A single case of New World screwworm in Texas has triggered fears of supply chain disruption, leading to a rally in U.S. cattle futures. The USDA is leading containment efforts, including releasing sterile flies, while Texas' governor has declared a state of disaster and called for accelerated construction of a sterile fly production facility.

The first U.S. case of New World screwworm in decades has been confirmed in a calf in La Pryor, Texas, raising concerns among ranchers and pet owners about potential decimation of cattle herds and local wildlife. The U.S. Department of Agriculture (USDA) is leading containment efforts, deploying workers to set fly traps, release sterile flies to halt reproduction, and inspect livestock at checkpoints. Fears of further infestations have contributed to a rally in U.S. cattle futures, as potential supply chain disruptions loom. Texas Governor Greg Abbott declared a state of disaster and urged the federal government to expedite the completion of a sterile fly production facility, originally slated for November 2027, stating it must be operational before summer 2027 to prevent a second season of spread. Some local officials and ranchers have criticized the USDA's preparedness and response.
The detection of the screwworm parasite poses a significant threat to the multi-billion-dollar Texas cattle industry, potentially causing widespread economic damage through livestock loss and supply chain disruptions due to quarantines and movement restrictions.