- Summary
LA PRYOR, Texas, June 5 (Reuters) – The quiet Texas cattle town of La Pryor has become ground zero in the fight against screwworm after the first U.S. case in decades was detected there, prompting a livestock quarantine and putting ranchers and pet owners on edge.
A calf at a ranch tested positive on Wednesday for the flesh-eating parasite, which left a gaping hole around its umbilical cord.
Ranchers in South Texas have been bracing for the arrival of screwworm for more than a year, as the flies progressed from Colombia through Central America, inching closer to the U.S. border. The parasite could decimate cattle herds and local wildlife.
U.S. Department of Agriculture Secretary Brooke Rollins has said that only one case has been confirmed, and that the agency was doing all it could to stop a spread that threatened Texas’ multi-billion-dollar cattle industry.
USDA WORKERS LEAD CONTAINMENT EFFORTS
On Friday, USDA workers fanned out across Zavala County, which borders Mexico’s Coahuila state, setting fly traps, releasing sterile flies to halt their reproduction and talking to ranchers.Major roads out of La Pryor were marked with blinking orange signs urging vehicles carrying livestock to pull into a checkpoint staffed with sheriffs and state personnel to inspect the animals for signs of screwworm.
Marcel Valdez, a retired teacher and Texas A&M University extension agent, recalled the last time screwworm appeared in South Texas, when he was a child in the 1960s.
As he sat on his truck’s tailgate watching stray cats eat food he put out, he recalled how screwworm-infested calves kicked and licked at their open wounds, the smell of rotting flesh as hundreds of larvae ate the animals alive, and the sharp smell of the black, tar-like medicine he used to treat them.
Item 1 of 3 Cows lie in a pasture, a day after the U.S. Department of Agriculture confirmed that New World screwworm was detected in a Texas calf, in La Pryor, Texas, U.S. June 4, 2026. REUTERS/Kaylee Greenlee
Now he worries most about younger cattle ranchers who have no experience treating the pest, the abundance of wild animals that could become vectors for spreading it and the limited number of sterile flies being produced.
“The screwworm multiplies so fast, it can get out of hand very, very quickly,” he said.
Other ranchers in South Texas lambasted the USDA’s efforts and called on Texas Governor Greg Abbott to declare a state of disaster to trigger federal relief funds.
At the same time, individual Texas counties were taking action.
Kinney County, adjacent to Zavala County, declared a disaster on Thursday.
“The USDA has had plenty of time to prepare for this and they are failing,” Brent Smith, the county attorney, wrote on X.
Rollins said on Thursday that screwworm had been projected to cross into the U.S. by last year, and that the Trump administration’s efforts staved it off, giving the USDA time to deploy a rapid response.
Fears of further infestations continued to rattle markets on Friday, extending a rally on U.S. cattle futures.
Heather Schlitz
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