A cattle parasite not seen in the U.S. for 60 years just showed up in Texas

The USDA confirmed a screwworm fly in a Texas calf on June 10—the first U.S. case since 1966. The parasite, which kills livestock in weeks if untreated, crossed north from Mexico. This threatens cattle ranchers in the Southern Plains and could block U.S. beef from countries that require parasite-free imports.