Phased Reopening after Screwworm Outbreak Starts July 7 in Arizona
The U.S. Department of Agriculture (USDA) is reopening cattle, bison, and equine imports from Mexico in phases after closing the border on May 11 due to the threat of the New World Screwworm (NWS).
The reopening will begin July 7 at Douglas, Arizona, identified as the lowest-risk entry point due to close collaboration with Sonoran officials.
The screwworm, a parasitic fly eradicated in the U.S. in 1966, has recently been spreading in Mexico. Its larvae burrow into wounds of animals, causing severe tissue damage and even death.
USDA Secretary Brooke Rollins stated, “We are continuing our posture of increased vigilance and will not rest until we are sure this devastating pest will not harm American ranchers.”
To combat the spread, the USDA has invested $21 million to modernize a sterile fly production facility in Mexico and is building a sterile fly dispersal center in Texas. These sterile male flies are released into affected areas to mate with females, preventing reproduction and reducing the pest population.
Additional ports are scheduled to reopen soon, including Columbus, New Mexico (July 14), Santa Teresa (July 21), Del Rio, Texas (August 18), and Laredo (September 15). Each phase will be assessed before moving to the next.
The USDA also expects a new screwworm fly factory in southern Mexico by July 2026 and will open a fly distribution center in Texas later this year. These measures aim to prevent reestablishment of the pest in U.S. livestock and wildlife.
The phased reopening ensures animal health protection while supporting cross-border trade, critical to U.S. agriculture and food supply chains.