US expands sterile‑fly program as New World screwworm resurges in Texas and New Mexico

The U.S. Department of Agriculture announced three new New World screwworm infections—a calf in La Salle County, Texas, a goat in Gillespie County, Texas, and a dog in Lea County, New Mexico—bringing the nation’s total to five cases. The parasitic fly, eradicated in the 1960s, is moving northward from Central America and threatens livestock across the Southwest.

Federal and Texas officials said they are deploying additional sterile flies in the affected areas, expanding production facilities, and using AI‑driven monitoring to help ranchers spot infections early. A new sterile‑fly production site is planned for Edinburg, Texas, and officials are evaluating an emergency authorization for a genetically engineered male‑only strain, NovoFly, which could double release numbers.

The outbreak has not yet produced domestically acquired human cases, and the dog’s travel history remains unclear. Authorities emphasize that previous eradication efforts relied on the sterile‑insect technique, and they are confident they can again contain the pest.