Estimated Time to Read: 7 minutes
Texas is staring down a familiar but dangerous threat: the New World Screwworm. Though it might sound like science fiction, this parasitic fly is very real, and it poses a serious danger to livestock, wildlife, and even household pets. The parasite hasn’t been a problem in Texas since the 1970s, but recent detections just across the border in Mexico have raised significant alarms.
What follows is not just a story of science and agriculture. It’s about how Texas, the USDA, and leaders at all levels of government are responding to a growing biosecurity challenge. From port closures and emergency plans to flying sterile insects across the sky, this unfolding response shows how high the stakes are, and how urgent the timeline may be.
What Is the New World Screwworm and Why Is Texas at Risk
The New World Screwworm, also known by its scientific name Cochliomyia hominivorax, is a parasitic fly that lays its eggs in the open wounds of live, warm-blooded animals. Once the larvae hatch, they burrow into the tissue, causing severe and often deadly damage to livestock, pets, wildlife, and in rare cases, people.
Although the pest was eradicated from the United States in the 1960s, it began migrating north again in 2022. It was recently detected in Ixhuatlan de Madero, Veracruz, Mexico—about 370 miles from the Texas border. With more than 10 million head of cattle, Texas is particularly vulnerable to the pest’s return.
In 1976, an outbreak in Texas caused $330 million in damages. Today, with higher cattle prices and inflation, the same kind of outbreak is estimated to cost more than $2 billion, not counting the added strain on supply chains and exports.
Screwworm Port Closures Shake Texas Cattle Markets
In May 2025, the U.S. Department of Agriculture (USDA) shut down southern ports to livestock imports from Mexico in response to the growing threat. A phased reopening had been set for July, but a new detection in Veracruz led the U.S. Secretary of Agriculture, Brooke Rollins, to pause that plan and keep ports closed indefinitely.
This has created real market tension. The United States imports between 1.2 and 1.5 million feeder cattle from Mexico each year. That’s about 4 percent of total slaughtered cattle in 2024. Losing that supply is already pushing prices up and putting pressure on feedlot operations.
The USDA’s July WASDE report shows that beef production in 2025 is expected to decline by 170 million pounds. For 2026, production is expected to increase by 540 million pounds, but that projection assumes that the screwworm remains out of the country and trade flows normalize.
Texas House Committee and Governor Abbott Mobilize State Response
On July 21, the Texas House Committee on Agriculture and Livestock held a hearing to take stock of the situation. Lawmakers discussed how to coordinate with the USDA, how to boost surveillance, and how ready Texas ranchers and wildlife officials are for what could come next.
It’s important to clarify that while the committee is holding hearings, the screwworm issue is not part of the agenda for the current special legislative session. Unless Governor Greg Abbott (R) amends the agenda, the legislature cannot pass any bills on the topic during this session.
Governor Abbott did not wait for the special session to begin, however, to begin addressing the issue at the state level. He directed the Texas Animal Health Commission and Texas Parks and Wildlife Department to form a Screwworm Response Team in June. This team is tasked with coordinating efforts, sharing information, and making sure everyone—from landowners to agencies—is aligned.
Texas Agriculture Commissioner Sid Miller (R) praised the move, stating,
“I’m pleased that Governor Abbott is activating the state agencies under his direct oversight, responsible for protecting animal health and wildlife, to respond to this dire threat. This pest poses a serious risk not only to Texas livestock and wildlife but also to the economic backbone of our rural communities. The Texas Department of Agriculture (TDA) will continue to work in collaboration with this response team to relay necessary updates as the spread of the New World screwworm approaches Texas.”
Source: Statement by Texas Agriculture Commissioner Sid Miller (R), 6.26.2025
Dr. Bud Dinges, the state’s veterinarian and head of the Animal Health Commission, has indicated that staff have been training for over a year. Abbott and others have stressed the need for constant communication, coordination, and quick action.
USDA’s Five-Pronged Plan to Eradicate the Screwworm
Secretary Rollins rolled out a multi-part plan to stop the pest, including reviving one of the most effective methods ever used in agricultural pest control: releasing sterile flies to interrupt breeding cycles.
One part of the plan focuses on stopping the screwworm in Mexico. The USDA invested $21 million in converting a facility there to produce over 100 million sterile flies each week. U.S. teams are on the ground, auditing Mexico’s efforts and providing technical help; however, it is estimated that this conversion will not be completed for another 12 to 18 months.
Another part of the plan focuses on border protection. Tick riders, or trained inspectors employed by the USDA and Border Patrol, are helping identify and treat stray animals. The USDA has also increased outreach to communities near the border and set up a buffer zone to monitor for new infestations.
Readiness is another priority. Emergency plans are being updated, treatments stockpiled, and unnecessary regulatory barriers are being cleared.
Then there’s infrastructure. The USDA is building a new fly dispersal facility at Moore Air Base in Edinburg, Texas, with a budget of $8.5 million. A domestic production facility is also in the works to increase capacity to as many as 400 million flies per week.
Innovation is the final component. The USDA is partnering with Texas universities and exploring new sterilization methods, including radiation and genetic modification. Public listening sessions are underway to help refine the response plan.
Why Dropping Billions of Flies Works
As strange as it sounds, this is one of the USDA’s greatest success stories. Female screwworm flies only mate once. When sterile males are released in large numbers, most females lay eggs that never hatch. The result is a rapid drop in the population without using toxic chemicals.
This method helped eliminate the screwworm from the southern U.S. decades ago. More than 94 billion sterile flies were released between 1962 and 1975. Now, that strategy is coming back on a larger scale, with updated tools and better coordination.
Planes carrying crates of sterile flies will soon be flying over South Texas and northern Mexico, working to break the pest’s life cycle before it gains a foothold.
Texas Takes the National Lead on Screwworm Eradication
The Edinburg facility has become a focal point in the national fight. Leaders from both parties and all levels of government have voiced support. Both Senators John Cornyn (R) and Ted Cruz (R), as well as Representatives Monica De La Cruz (R) and Tony Gonzales (R), have all introduced or backed legislation to expand sterile fly infrastructure.
Agricultural groups like the Texas Farm Bureau and Texas Cattle Feeders Association have also stepped up to praise the coordinated efforts and call for continued investment. Many see Texas as the key to stopping this pest before it spreads nationwide.
The facility in Edinburg, if given additional resources through legislation currently stalled in Congress, would not be completed for an estimated 3 years, however.
Conclusion: Texas Is America’s Firewall Against the Screwworm
The return of the New World Screwworm presents a serious challenge. It threatens not only the livestock industry, but wildlife, rural economies, and the national food supply. Texas finds itself at the center of the response.
Even though the issue is not on the current special session agenda, state officials are taking it seriously. The House Committee hearing and Governor Abbott’s directive are early steps that show Texas is preparing, even if formal legislation must wait.
With billions of sterile flies being raised, new facilities breaking ground, and researchers and ranchers working side-by-side, Texas is taking action to stop the screwworm before it becomes a crisis.
The threat is real. The timeline is short. Will Texas be ready?
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