US screwworm outbreak threatens Texas cattle industry

US authorities have confirmed a resurgence of the New World screwworm fly in Texas, the first livestock‑related cases in about 50 years. Six large cattle have been infected, and additional cases have been identified in New Mexico. The parasite’s larvae feed on live tissue, posing health risks to both animals and humans.

The USDA and CDC have activated emergency response plans, emphasizing the release of sterilized male flies to break the pest’s reproductive cycle. The only existing sterile‑fly production facility operates in Panama, producing 100 million flies weekly, while a new plant in Metapa, Mexico, is expected to increase output this summer. A U.S. facility under construction at Moore Air Force Base in Texas will not reach full capacity of 300 million flies per week until after November 2027.

Officials warn that uncontrolled spread could raise treatment, monitoring and labor costs for producers. A 2015 outbreak in Texas affected 1.5 million cattle and caused $375 million in losses. The FDA has granted conditional approvals for certain veterinary drugs, and the USDA has begun shipping supplies to affected farms. Quarantine measures and drug support are being deployed to contain the parasite.