New World Screwworm
While USDA eradicated New World screwworm from the U.S. in 1966, there’s a constant risk of re-introduction. The parasitic fly larvae eat the living tissue of warm-blooded animals, such as cattle, causing serious, often deadly damage. The National Cattlemen’s Beef Association has warned it’s not a matter of if — but when — the pest makes its way back into the U.S.
Surveillance, reporting and veterinary partnerships are framed as critical ways to prevent a single case from becoming a national crisis.
From the evolving H5N1 virus to the looming screwworm threat, discover why a line of separation is the new strategic foundation for safeguarding the U.S. milk supply in 2026.
Agriculture Secretary Brooke Rollins broke ground on a $750 million sterile fly facility in Texas and confirmed the border will remain closed until the New World screwworm threat is pushed back from the U.S. border.
A new genetic innovation from the Agricultural Research Service aims to produce 100% sterile male flies, maximizing facility efficiency and safeguarding the U.S. livestock industry from NWS.
Following extensive industry feedback, the updated guide provides a science-based roadmap for states, ranchers and veterinarians to combat potential NWS outbreaks.
Kansas State Veterinarian Dr. Justin Smith outlines a coordinated plan built on surveillance, targeted treatment and movement controls to protect cattle operations while preserving business stability.
Driving innovation to combat NWS and prevent its northward spread.
With a New World screwworm case now less than 200 miles from the U.S. border, Seth Meyer says the growing threat adds risk and uncertainty for cattle producers making critical calving-season decisions.
It’s time to start thinking about how to protect herds from New World screwworm before it reaches the U.S.
Texas producers need to remain on alert as NWS continues to move north. The newest detection is in the state of Tamaulipas.
This facility will increase the range of sterile fly release and bolster preparedness for New World screwworm.
Federal government will cut the bureaucracy to support the dairy industry, focused on tougher measures to stop major animal disease problems and improve labor availability.
NWS Response Playbook developed as a resource to help animal health officials and responders manage and adapt their response if New World screwworm is found in the U.S.
“Most screwworm migration does not come from adult flies making heroic flights northward. Instead, it comes from the movement of infested animals — cattle, deer, wildlife — and yes, even in rare cases, people. Wherever the animal goes, the parasite goes with them,” says Dr. Christopher Lee.
Historically, colder temperatures have played a crucial role in controlling New World screwworm’s geographical spread.
U.S. Department of Energy’s National Nuclear Security Administration’s is partnering with Texas A&M University to advance the sterile fly technique to halt NWS reproduction.
With New World screwworm within 70 miles of the U.S.-Mexico border, the livestock industry is on high alert. USDA continues to fight the northward spread of the parasite while debate continues on the border closure.
USDA says this is now the northernmost detection of NWS during this outbreak, and the one most threatening to the American cattle and livestock industry.
New World screwworm was essentially eradicated in the U.S. in 1966, but the persistent pest has rebounded through considerable geography in the past year, prompting the closure of the U.S./Mexico border to cattle in recent months.
The next step to battling NWS is using swormlure, a synthetic bait designed to attract adult screwworm flies, combined with an insecticide to combat the pest.
The image, the smell, the emotions: five cattle producers and veterinarians from around the world share their first-hand experience with New World screwworm.
Secretary Rollins takes decisive action and shuts down cattle, bison and equine trade due to further northward spread of the devastating pest in Mexico.
As the fight to keep the flesh-eating parasite out of the U.S. intensifies, the economic impact on ranchers and the industry is top of mind. “This pest will be one that leaves quite a mark on our economy,” says one veterinarian.
A dangerous livestock pest, the New World Screwworm, has resurfaced in Central America, prompting a U.S. livestock import ban and renewed warnings for producers to watch for signs of infestation.
Secretary of Agriculture Brooke Rollins announces plans to reopen Moore Air Base in Texas as a New World screwworm sterile fly distribution facility. Long-term production is anticipated to be 300 million sterile flies per week.
NCBA applauds Secretary of Agriculture Brooke Rollins’ aggressive efforts to suspend Mexican cattle, horse and bison imports, saying Mexico’s corruption and mismanagement has caused the pest to spread closer to the U.S.