USDA continues efforts to combat threat of New World screwworm
As the threat of New World screwworm (NWS) creeps closer to the U.S. border, the U.S. Department of Agriculture (USDA) is continuing its efforts to combat the invasive pest.
In June, the department rolled out a five-pronged plan aimed at detecting, controlling and eliminating NWS before it crosses the border, combining prevention, preparedness and active suppression to stay ahead of the fly’s northward march.
Recently, USDA added a few more tools to its toolbox in fighting NWS.
Collaborative effort
At the beginning of November, U.S. Secretary of Agriculture Brooke Rollins led a trade mission to Mexico City, in what she described as the “largest trade mission in the department’s history to Mexico.”
According to a Nov. 13 USDA press release, the mission brought together 41 U.S. businesses, 33 cooperators and ag advocacy groups, six state departments of agriculture and 150 participants who conducted more than 500 business-to-business meetings over the course of three days.
Discussion addressed the ongoing NWS outbreak and collaborative efforts being made to control and eradicate the pest, as well as expanding Mexican market access for American ag products.
In an exclusive interview with Reuters following the mission, Rollins notes while the U.S. is not ready to open its border to Mexican cattle imports yet, she is pleased with the country’s recent efforts to contain the pest and says President Donald Trump has made it a priority to reopen the border, which has been closed to livestock trade since May.
“We’re still not at the point where I am comfortable opening the ports, but I think every day that goes by we get a little bit closer,” Rollins tells Reuters. “I want to have every confidence we have overturned every stone, we understand every nuance and we are deploying every tool in the toolkit.”
“The trading and diplomatic relationship between our two countries is of the utmost importance to President Trump and American farmers and ranchers,” she says in the press release. “Whether it is securing the Southern Border from illegal migration, combating NWS or expanding market access for American agricultural products, we are working every day to put American interests first.”
Dispersal facilities
Additionally, on Nov. 13, USDA announced the opening of a sterile fly dispersal facility in Tampico, Tamaulipas, Mexico, which will allow the department to release sterile male screwworm flies aerially across northeastern Mexico.
USDA explains aerial dispersal helps cover larger areas – including those inaccessible from the ground – making it a critical tool in the agency’s containment strategy.
“The opening of the Tampico, Mexico sterile fly dispersal facility is another incredibly important tool in our arsenal to stop the spread of screwworm,” Rollins states. “The facility will ensure flexibility and responsiveness in northern Mexico, giving us a greater ability to drop sterile flies and continue to push the pest south.”
USDA also announced it will invest $21 million to support renovation of a fruit fly facility in Metapa, Mexico, which will double as a NWS production facility when it is completed in the summer of 2026.
Further, the agency has begun construction on a sterile fly dispersal facility at Moore Air Base in Edinburg, Texas, which is projected to begin operations in early 2026, and the department is expediting construction on a production facility in southern Texas with a targeted capacity of 300 million sterile flies per week.
Meanwhile, USDA continues to disperse 100 million sterile flies per week in Mexico.
New website
Among the lineup of initiatives rolled out in November, USDA also launched a new website to centralize information regarding NWS, including updates on surveillance, guidance for producers, maps of risk zones, ongoing efforts and resources for stakeholders in both the U.S. and Mexico.
The website includes targeted resources for everyone from livestock producers, wildlife professionals, veterinarians, animal health officials and pet owners to healthcare providers, researchers, drug manufacturers and the general public.
It also includes the latest USDA-verified information on cases and response activities, as well as information from USDA’s partner agencies like the Food and Drug Administration, the Department of Energy, the Department of Homeland Security, the Environmental Protection Agency and the Department of State.
The agency notes the site aims to increase transparency, keep producers informed and provide a single, reliable source for developments in the fight against NWS.
“The Trump administration is leading a whole-of-government effort to protect our nation’s cattle industry from NWS. To ensure timely and effective communications, this new unified website will be a one-stop shop for all screwworm related information and will help our stakeholders be better informed as new information comes available,” Rollins says.
“We are grateful for robust interagency collaboration, and we continue to work every day with our state and industry partners to implement our screwworm plan. This is a national security priority, and it has the full attention of our team,” she adds.
Current movement
While Mexico continues confirming new NWS cases, the department notes the overwhelming majority have remained in the far southern part of the country, with no significant northward expansion in recent months.
The two northernmost detections occurred in Nuevo León, Mexico in September and October – approximately 70 and 170 miles from the U.S. border – in young cattle transported from Chiapas, Mexico.
The agency asserts no additional detections have occurred in the area and neither case remains active.
USDA also maintains the pest has not been detected in the U.S., with over 30,000 fly samples trapped in Texas, Arizona and New Mexico and tests on 6,600 wild animals across 28 species in 120 U.S. counties all confirming negative for NWS infestation.
Hannah Bugas is the managing editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.
