New World screwworm detected in Texas, posing threat to cattle industry

The New World screwworm, a parasitic fly that had been absent from U.S. livestock for decades, has been confirmed in a 3-week-old calf in La Pryor, Texas, near the U.S.-Mexico border. Agriculture Secretary Brooke Rollins announced the detection on June 3, 2026. The larvae of this fly feed on the living tissue of warm-blooded animals, including livestock and, in rare cases, humans and pets. While the parasite does not pose a food safety risk, a widespread outbreak could result in significant financial losses for the livestock industry and further increase beef prices, which are already at record highs. This is the first confirmed case of New World screwworm in Texas since 1966. Texas Agriculture Commissioner Sid Miller criticized the USDA for its slow response and has called for more federal resources to combat the threat. The USDA has begun releasing sterilized male flies in the area to control the population and has established a 12-mile quarantine zone to restrict the movement of warm-blooded animals. State veterinarians are advising ranchers and pet owners within the quarantine zone to adhere to movement restrictions as eradication efforts proceed. The U.S. cattle herd is currently at its lowest level in 75 years, and a major outbreak of screwworm could exacerbate supply issues and increase costs for consumers.