APHIS Lifts Screwworm Restrictions in Two Texas Zones
USDA's APHIS has released two New World screwworm infested zones in Texas, removing movement requirements for livestock and pets in parts of five counties.
The US Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) has approved the release of two New World screwworm infested zones in Texas. The agency announced the decision on August 31, 2026. It is the first time an infested zone has been released in the state since the initial case was confirmed.
The action lifts all movement requirements related to the parasitic infestation for livestock and pets within the boundaries of the two zones. According to APHIS, all other interstate and international export requirements that are not specific to this animal health response remain in effect.
Zones Released and Response Activities
The two zones being released are Infested Zone 02.A and Infested Zone 03. Zone 02.A includes portions of La Salle and Webb counties. Zone 03 covers parts of Gillespie, Kerr, and Kimble counties.
State and federal experts confirmed both zones met all requirements outlined in APHIS's New World Screwworm Response Playbook before the release was approved. Response activities conducted jointly by the Texas Animal Health Commission (TAHC) and APHIS included establishing domestic animal movement requirements with inspections, wildlife and fly surveillance, and strategic releases of sterile flies.
Dudley Hoskins, USDA under secretary for marketing and regulatory programs, praised the state's cooperation. "The Texas Animal Health Commission has been an outstanding partner throughout our response to New World screwworm," Hoskins said in the agency's announcement. The decision followed concurrence from Texas State Veterinarian Bud Dinges and the TAHC.
Background on the Outbreak
APHIS confirmed the first US case in this outbreak on June 3, 2026. The agency identified New World screwworm larvae in the umbilical region of a three-week-old calf in Zavala County. In response, USDA and Texas officials established a 20-kilometer infested zone with quarantines and movement controls.
Authorities also began ground-based releases of sterile insects to complement existing weekly aerial releases of four million sterile flies. Border surveillance and wildlife management efforts were intensified.
Hoskins expressed confidence in the eradication effort at the time of the initial detection. "The United States has defeated this pest before, and we will do it again," he stated.
The Threat to Animals
Larvae of this parasite burrow into the living flesh of warm-blooded animals through open wounds. This causes significant tissue damage that can be fatal to livestock, pets, and wildlife if left untreated.
APHIS has stated that these parasites do not contaminate meat or other food products. Protocols from the Food Safety and Inspection Service are designed to identify infected animals before they enter the commercial food supply.
Several infested zones in Texas remain in place following this release. APHIS said it will continue working with the Texas Animal Health Commission to evaluate conditions for additional zone releases in the future.
