A South Texas screwworm calf case has prompted federal and state officials to establish a livestock quarantine zone in Zavala County after the New World screwworm was confirmed in a young calf near La Pryor. The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service confirmed the detection on Wednesday, June 3, 2026, in a 3-week-old calf in Zavala County, Texas. Officials said the larvae were found in the calf’s umbilical area and that no ad