First Case of New World Screwworm Detected in Coahuila, Mexico

The Texas Department of Agriculture confirmed a New World Screwworm case about 119 miles from the Texas border, near Zapata, Texas, and north and west of the Rio Grande Valley.

Aberdeen Angus Cattle Feeding in a Feedlot at Sunset

Angus cattle feeding in a feedlot at sunset

JavierAndrés - stock.adobe.com

AUSTIN, TEXAS (RFD NEWS) — Texas Agriculture Commissioner Sid Miller is warning producers to stay alert after the first confirmed detection of New World screwworm in the Mexican state of Coahuila, bringing the pest closer to the U.S. border.

According to the Texas Department of Agriculture, the detection was confirmed roughly 119 miles from the Texas border, placing it near the same latitude as Zapata, Texas, and north and west of the Rio Grande Valley.

“This screwworm detection in Coahuila is a serious wake-up call,” Miller said. “New World screwworm has now been found only 119 miles from the Texas border — at roughly the same latitude as Zapata, Texas, and north and west of the Rio Grande Valley.”

New World screwworm is a parasitic fly whose larvae infest living tissue in warm-blooded animals, causing severe wounds known as myiasis. Officials say adult flies lay eggs in open wounds or mucous membranes, and once the larvae hatch, they burrow deeper into tissue, rapidly worsening injuries and potentially killing livestock if left untreated.

The pest poses a threat to cattle, horses, sheep, goats, wildlife, pets, and in rare cases, humans.

“This threat is advancing fast, and every Texan needs to take notice,” Miller said.

Texas officials say the state has expanded its biosecurity response in recent months, including additional trapping efforts in high-risk border areas, export facilities, and port zones.

“Texas is on the front lines,” Miller said. “Under my direction, the Texas Department of Agriculture has launched an aggressive biosecurity response, including expanded trapping with our innovative TDA Swormlure in high-risk border zones, export pens, and port areas. We are conducting weekly surveillance, maintaining rapid response capabilities, and working in close coordination with federal partners and Mexico.”

Miller said Texas is relying on lessons learned from past eradication efforts, including the sterile insect technique that helped eliminate screwworm from the U.S. decades ago.

“We’ve beaten the screwworm before through relentless vigilance and the sterile insect technique. We will beat it again — but we must deploy every tool available,” Miller said. “Texas will stay vigilant, stay aggressive, and do whatever it takes to protect our livestock, our pets, our food supply, and the livelihoods of our ranchers.”

Texas producers who suspect an infestation are encouraged to contact their veterinarian immediately or call the Texas Department of Agriculture hotline.

More information is available from the U.S. Department of Agriculture at www.Screwworm.gov.

Related Stories
The 91st anniversary of Black Sunday highlights how the Dust Bowl disaster led to modern soil conservation programs still shaping U.S. agriculture today.
A new partnership with the Montana Beef Council is bringing protein-packed refuel stations to high school sports tournaments across the state.
As budget hearings continue on Capitol Hill, policymakers focus on long-term solutions to stabilize the fertilizer market to support U.S. farmers.
Rural driving conditions increase the risk of serious collisions with animals.
Weak soybean sales and soft wheat demand contrast with solid corn export strength.
AFBF Economist Dr. Faith Parum break down new survey findings on fertilizer affordability and producer sentiment heading into the 2026 growing season.

Marion is a digital content manager for RFD News and FarmHER + RanchHER. She started working for Rural Media Group in May 2022, bringing a decade of digital experience in broadcast media and some cooking experience to the team.

LATEST STORIES BY THIS AUTHOR:

Aris Georgiadis with Dairy Management Inc. joined us to discuss the “Dairy Does More” campaign and how it is working to boost demand for dairy.
While social media has labeled the possible event a “Godzilla El Niño,” experts say the intensity remains uncertain—but the signal for a stronger pattern is there.
Rising diesel and energy costs are squeezing farmers and rural communities, increasing production expenses and raising concerns about consumer demand for beef even as U.S. meat exports regain the Australian market.
Farmer John Jenkinson shares the latest on planting conditions in Kansas and what producers are facing this season.
Rising input costs may squeeze margins and shift planting decisions. Scott Metzger with the American Soybean Association discusses fertilizer market pressures and what is at stake for farmers as planting season ramps up.
Texas ranchers and lawmakers warn of renewed New World screwworm risks, highlighting prevention efforts, border concerns, and the role of sterile flies in protecting U.S. livestock.
Agriculture Shows
Hosted by Scott “The Cow Guy” Shellady and RFD News Markets Specialist Tony St. James, Commodity Talk delivers expert insight into the day’s ag commodity markets just before the CME opens. Only on RFD-TV and Rural Radio SiriusXM Channel 147.
A look at the news, weather and commodities headlines that drove agriculture markets in the past week.
Everything profits from prairie. Soil, air, water — and all kinds of life! Learn how you can improve your land with prairie restoration, cover crops and prairie strips, while growing your bottom line.
Special 3-part series tells the story of the Claas family’s legacy, which changed agriculture forever.