A Livestock Pest Thought Eliminated 60 Years Ago Just Returned to Texas

The screwworm fly, a parasitic insect that ate livestock from the inside, vanished from the U.S. in 1966. Two cases just appeared in Texas cattle in June 2026. The fly's larvae burrow into living tissue and breed fast. Its reappearance suggests a containment system that protected the U.S. for decades may have failed.