USDA confirms new world screwworm in Texas cattle near Mexico border

On June 4, 2026, the U.S. Department of Agriculture announced the detection of the New World screwworm parasite in a calf from La Pryor, Zavala County, Texas – the first U.S. case since 1966. USDA Secretary Brooke Rollins told Congress that the agency does not consider it a plague and can isolate each case. Immediate actions include a 20‑kilometer quarantine zone, movement controls, on‑the‑ground response teams and the release of sterile flies to prevent spread.

Rollins cited lax border policies as a factor in the incursion and warned that unchecked dissemination could cost up to $1.8 billion in cattle losses. She reassured consumers that the worm does not infest meat, so the food supply remains safe.