Texas confirms screwworm parasite 60 years after U.S. eradication

USDA-APHIS confirmed New World screwworm in a Texas calf on June 10, 2026—the first U.S. detection since the parasite's eradication in 1966. The fly, which kills untreated livestock within weeks, migrated northward from Mexico and was detected within 60 miles of the Texas border in May. The confirmation poses serious economic risk to Southern Plains cattle operations and complicates beef exports to pest-free markets.