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
RFD News correspondent Frank McCaffrey spoke with the Texas Shrimp Association at the Port of Brownsville about the future of the USDA’s new Office of Seafood.
Higher cow numbers and slightly stronger output per cow pushed milk production above last year.
Food inflation is still building in 2026, with beef leading pressure while eggs and dairy offer some relief.
Rotational grazing can improve pasture use and soil health while helping control feed and drought-related risk.
March cold storage data showed generally tighter year-over-year stock levels across several key meat and dairy categories.
“Flat FFA members” help students share life and agriculture across states

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:

Farm Credit’s Christy Seyfert joined us to discuss the ag industry’s push for swift Farm Bill action as it heads toward a House vote.
Bridge payments are helping, but many producers still face losses and tight margins. AEM’s Curt Blades joins us to discuss how the current farm economy is pressuring equipment demand.
Purdue economist Dr. Joana Colussi discussed the U.S. and Brazil’s reliance on imported fertilizers and their impact on global food security amid rising input costs.
RFA President and CEO Geoff Cooper joined us to discuss the proposed E15 amendment in the Farm Bill, industry reaction to the legislation, and the outlook for year-round E15 sales.
USDA Secretary Brooke Rollins plans a farm visit in Missouri, hinting at a possible fertilizer relief announcement on RFD-TV earlier this week. USDA also restructures its research infrastructure and launches new food-safety centers.
Dry conditions have severely impacted key winter wheat states with persistent moisture deficits. As quality declines, analysts warn some crops may be lost despite upcoming rain.
Agriculture Shows
Created by former Louisiana Farm Bureau PR Director and former host Regnal Wallace, “This Week in Louisiana Agriculture,” is one of the state’s longest-running TV programs.
From the rapid technological advances in the business of farming to the policy that helps shape the industry, growers get unparalleled perspective from these guys. Max Armstrong, Mike Pearson and Greg Soulje: the names producers have long known and trusted for agriculture news, weather, and commentary.
Watch Rural Evening News on RFD Network to catch up on that day’s news surrounding agriculture and markets from across the world.
Every day on RFD Network, “Market Day Report” delivers LIVE coverage of agribusiness news, weather, and commodity market information from across the world. Our commodity markets coverage is updated every half hour to bringyou the latest agriculture news.