EDINBURG, Texas – USDA Secretary Brooke Rollins has announced plans to build and operate a $8.5 million New World screwworm (NWS) sterile fly dispersal facility at the former Moore Air Force Base in Edinburg, with a five-pronged plan to enhance the agency’s ability to detect, control and eliminate this pest.

“The United States has defeated NWS before, and we will do it again,” she said in a June 18 press conference at the former Air Force Base, just 20 miles from the Mexico border.

Rollins said these actions are necessary to finish the fight against NWS, and protect the United States: “We do not take lightly the threat NWS poses to our livestock industry, our economy, and our food supply chain.”

She added, “The United States government will use all resources at its disposal to push back NWS, and today’s announcement of a domestic strategy to bolster our border defenses is just the beginning. We have the proven tools, strong domestic and international partnerships, and the grit needed to win this battle.”

NWS is a pest that causes serious and often deadly damage to livestock, wildlife, pets and, in rare cases, humans, according to the USDA. While NWS has been eradicated from the United States for decades, recent detections in Mexico as far north as Oaxaca and Veracruz, about 700 miles away from the U.S. border, led to the immediate suspension of live cattle, horse and bison imports through U.S. ports of entry along the southern border May 11.

Closed in 1963 and transferred to the USDA, the former Moore Air Force Base played a key role in the previous NWS eradication effort in the 1960s, the USDA said, adding it successfully eradicated self-sustaining screwworm populations within the continental United States by 1966.

Grant Dewell, Iowa State University beef extension veterinarian, told Farm World, “A U.S. sterile fly installation will be critical to controlling the spread of NWS out of Mexico. The focus the last 20-plus years has been based in Panama, which was effective until the recent increase in uncontrolled cattle movements in Central America.

“Re-establishing a sterile fly buffer zone along our border will be necessary to protect U.S. livestock,” he added. “Hopefully, the spread can be stopped in Southern Mexico, but we need to be prepared if NWS continues to move north.”

Rollins said the dispersal facility will be completed by the end of 2025, allowing the USDA to aerially disperse sterile male flies to mate with wild female flies at the border and northern Mexico, resulting in no offspring. After the dispersal facility groundbreaking ceremony at the former base, she met with the USDA’s Animal and Plant Health Inspection Service’s (APHIS) cattle fever tick riders along the Rio Grande River.

The agency said cattle fever tick riders are USDA-employed, horse-mounted patrol inspectors who monitor the Texas-Mexico border to prevent the spread of cattle fever ticks. In the event NWS advances northward into the U.S., these tick riders will play a crucial role in spotting and combating this pest, the agency added.

According to APHIS, the Sterile Insect Technique, a method of biological pest control, is the only option available that has been successfully used to eradicate NWS. It involves mass-rearing male NWS flies, sterilizing them with radiation, and then releasing them into the wild to mate with wild females. Since the females only mate once, the resulting sterile matings lead to a decline in the wild population and, eventually, eradication, the agency added.

Rollins said the first of the five-pronged plan to eradicate NWS will be to stop the pest from spreading in Mexico. She said the USDA’s recent $21 million expenditure went toward renovating an existing fruit fly production facility in Metapa, Mexico, which will provide an additional 60-100 million sterile flies a week to stop the spread, on top of the over 100 million sterile flies already produced in Panama.

She added the USDA is working closely with Mexico to improve its surveillance and detection of NWS, which includes, but is not limited to, regularly providing traps, lures and technical expertise to Mexico.

She said the second part will be protecting the U.S. border. She added the USDA will support Mexico’s strategic trapping along their shared border and ensure it receives regular reporting as an early warning intervention, as well as escalate communications and public outreach along the U.S.-Mexico border to create a “barrier zone of vigilance,” boosting as close to real time as possible awareness of NWS. The cattle fever tick riders, in collaboration with U.S. Customs and Border Protection and state partners, will intercept and treat stray and illegally introduced livestock.

She said the third part will be to maximize readiness by the USDA, partnering with state animal health officials to update and finalize emergency management plans and support federal, state, and local responders in training on and practicing for a potential response.

Rollins said the fourth part will be “taking the fight to the screwworm.” Because sterile NWS flies are one of the most important and proven tools for eradicating the pest, she said the USDA will immediately begin building the sterile insect dispersal facility at the former air base.

She said the fifth part is the USDA will pursue “innovative research to improve sterile insect technology, exploring development of better traps and lures, exploring next-generation NWS treatments, and assessing the potential use and practicality of additional strains or genetically-modified versions of the pest,” as well as e-beam (a method of sterilization that uses high-energy electrons to kill microorganisms on products), and other radiation technology for the production of sterile flies.

Rollins added the USDA will strengthen partnerships with land-grant universities in border states such as Texas, Arizona and New Mexico, to facilitate local training, trap deployment, surveillance validation, and stakeholder outreach.