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
Texas A&M livestock economist Dr. David Anderson joins Tony St. James to discuss the geopolitical tensions and U.S.-Mexico border closure that are leading to sharp swings in the cattle market.
Arizona producers are proving that desert farming and water conservation can coexist through technology, reuse, and efficiency — reinforcing both food security and environmental stewardship.
Caleb Ragland, president of the American Soybean Association (ASA), shares his reaction to news of soybean sales to China, which is considered both “welcome news” and a return to near-normal trade relations.
Rabobank’s outlook signals a tightening margin environment, emphasizing the need for cost control, trade stability, and clearer policy signals heading into 2026.
Farm Bureau Economist Faith Parum discusses key outcomes from the U.S.-China trade agreement and the benefits of expanding trade across Southeast Asia.

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:

A booming butterfat market is good for some dairy products but threatens efficiency and margins for cheesemakers unless protein levels catch up
Duane Simpson, CEO of the National Council of Farmer Cooperatives (NCFC), joined us in Monday’s Market Day Report to share his perspective on the USDA’s plan and potential impact on producers.
While treatable with a vaccine, anthrax is a dangerous threat to cattle herd health if not identified and treated immediately.
UC Davis Professor and Extension Specialist Dr. Frank Mitloehner joined us on Friday’s Market Day Report to preview the festivities and share why this event has become such a special tradition for the ag community.
Beal joined us on Friday’s Market Day Report to discuss her election to NASDA’s presidency, challenges facing American agriculture, and her background as a Mainer and dairy farmer.
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.