With 11 confirmed cases of a flesh‑eating parasite now inside the United States—10 of them in Texas—state lawmakers gathered in Austin to discuss next steps for combatting a threat ranchers say could devastate cattle, wildlife, and rural communities.
“For Texas, this is no longer a distant concern,” began State Rep. Ryan Guillen (R–Rio Grande City) during a Thursday committee hearing, highlighting that the agricultural community has been sounding the alarm on the New World screwworm for more than 16 months.
Guillen chairs the House Committee on Agriculture & Livestock.
“The recent detection and confirmation of 11 cases within our state’s borders has transformed what was once viewed as a foreign pest into a clear and present threat to our livestock industry, our wildlife populations, our companion animals, our landowners, and the rural communities whose livelihoods depend on agriculture and wildlife resources,” he added.
During the hearing, lawmakers heard updates on suppression efforts from federal and state officials and also explored additional action steps needed for the total eradication of the New World screwworm. Experts say its re-appearance is a result of both Mexican cartel activity and the open border policies of the Biden administration.
Dudley Hoskins, U.S. Department of Agriculture under secretary for marketing and regulatory programs, discussed the whole agency approach that is being taken and highlighted the recent announcement of the USDA’s Grand Challenge project recipients.
The grand challenge “called on innovators from federal and non-federal entities to help in the efforts to prevent the spread of NWS by developing high-impact projects to enhance detection, control, and eradication readiness.”
After receiving 226 applications seeking about $664 million, the USDA announced earlier this week that it had awarded $105 million to 40 project applicants.
Admiral Michael Schmoyer, director of the New World Screwworm Directorate, highlighted the agency’s surveillance work in wildlife and the work to procure additional treatment options.
Schmoyer emphasized the need for Texans to report infestations when they occur, so the USDA is able to deploy resources, such as sterile flies, into the infested area.
Dr. Timothy Schell, director for the Center for Veterinary Medicine, updated the committee on the U.S. Food and Drug Administration’s authorization of 10 emergency and three conditional drugs for use.
Despite strong stakeholder interest, Schell said that, as of this time, there is no FDA-approved medicated feed for either cattle or deer to use in treating screwworm.
Texas Animal Health Commissioner Executive Director Dr. Lewis Dinges informed the committee of the creation of “infestation zones,” which are intended to help control the spread.
Dinges explained that once a screwworm case has been confirmed, a 12-mile radius around the case is established as a quarantine zone or “infestation zone.” Livestock can be moved out of these areas but must be inspected, identified, and treated first.
Although the practice of animal movement control does not appear to have been used when the screwworm was eradicated from the U.S. in the 1960’s and 70’s, Dinges highlighted that more sterile flies were available then than are currently available.
“They had 200 million sterile flies being produced a week at Moore Air Base being released,” said Dinges. “But now we don’t have that number of flies, and that’s what gets us behind.”
Dinges explained that due to the lack of flies to distribute to stop the northern spread of the pest, animal movement control is needed to help “deter the spread.”
The screwworm was first confirmed in the U.S. on June 3 in a calf from Zavala County. As of publication, 11 additional cases have been confirmed—10 of which are located in Texas, with the last case confirmed on June 12.
Following the confirmed infestation, Secretary of Agriculture Brooke Rollins, along with other experts, have blamed the advancement of the pest on Biden-era open border policies.
Senior Fellow for the Texas Public Policy Foundation’s Ammon Blair published a commentary arguing that the return of the screwworm is due to a collapse in the a biological containment barrier in 2021 at the Darian Gap in Panama. This collapse occurred because of the increased traffic of illegal aliens heading to the U.S. southern border.
Mexican authorities confirmed the first screwworm case in 2024, by which time it had already spread across central America into southern Mexico.
“Mexican officials’ complicity in cartel control over these routes turned mass migration into a gray-zone weapon that expanded smuggling infrastructure and increased pressure on the U.S.-Mexico border,” wrote Blair.
Mexican cartels reportedly move approximately 800,000 head of cattle per year from Central America to Mexico using fake ear tags and falsified veterinary records, allowing them to “bypass government checkpoints, sanitary inspections, and taxes.”
This trade is worth around $320 million annually.
“Once inside Mexico, the animals are laundered into the legal system, where they can enter feedlots or reach federally inspected Tipo Inspección Federal (TIF) slaughter plants used for domestic processing and exports,” wrote Blair.
Mexico exported around 1.25 million head of live cattle in 2024, with an estimated value of $1.3 billion. Following the pause in the live cattle trade, Mexico expanded its processed beef exports to the U.S., which rose 23 percent in the first four months of 2026.
Blair argued that in light of past statements made by the Secretary of Agriculture Brooke Rollins on how food security is national security, the spread of the screwworm should be seen as the national security threat it is.
“The return of NWS couldn’t come at a worse time for the American beef industry. U.S. cattle inventory has fallen to a 75-year low — the smallest national herd since 1951 — while beef imports have reached record levels,” wrote Blair. “By maintaining high levels of agricultural trade while cartels control significant portions of the supply chain, including the laundering of smuggled cattle, Mexico deepens U.S. dependence.”
On Wednesday, Gov. Greg Abbott announced that the USDA is providing additional funding to the Texas Animal Health Commission to help combat the New World screwworm, specifically allowing for the hiring of 15 employees—10 of which will be field inspectors.
Abbott has also announced the creation of a website with information on the screwworm. The site features information on how to report suspected screwworm cases, an infestation case map, and a direct link to Texas A&M’s New World screwworm preparedness and response online course.
