Domestic Dispersal Facility Is Ready to Drop Sterile New World Screwworm Flies

Secretary of Agriculture Brooke Rollins was in Edinburg, Texas, on Feb. 9 for the grand opening of the USDA Animal and Plant Health Inspection Service (APHIS) sterile fly dispersal facility at the Moore Air Base Facility. This facility expands USDA’s ability to disperse sterile flies along the border and into the U.S., if necessary.

The dispersal facility is a key piece of USDA’s efforts to protect the American livestock industry from New World screwworm (NWS) — a pest that would devastate ranchers if it made its way across the border.

Dudley Hoskins, USDA undersecretary of marketing and regulatory programs, says: “This is not mission accomplished. This is job well-done today. Let’s get to work and finish the job.”

Rollins says: “The Trump administration continues to bring the full force of the federal government to fight New World screwworm. This sterile fly dispersal facility was a high-priority project, and our team delivered it in record time. This new facility is a monumental achievement for our domestic preparedness efforts, but we are also diligently working to stop the spread of screwworm in Mexico, conduct extensive trapping and surveillance along the border, increase U.S. response capacity and encourage innovative solutions. We will never stop fighting to protect American agriculture. USDA, through a whole-of-government approach, will continue to hold Mexico accountable for mitigating the spread of this dangerous pest.”

Why The Sterile Fly?

The facility will use the sterile insect technique — an effective, science-based approach that releases sterile male flies into targeted areas to disrupt reproduction and gradually reduce NWS populations. This tool is critical to stopping the pest before it can move farther north.

Sterile insect technique, when paired with surveillance, animal movement restrictions and education and outreach, is a proven and effective tool for controlling and eradicating NWS. Female NWS flies only mate once in their lives, so if they mate with a sterile male, they lay unfertilized eggs that don’t hatch. Releasing sterile flies just outside of affected areas helps ensure flies traveling to new areas will only encounter sterile mates and will not be able to reproduce.

Sterile insects are dispersed through aerial dispersal or ground release. Aerial operations are preferred because they allow for dispersal at a steady rate through a large area and put sterile insects in areas unreachable from the ground. Ground release is used when there is a need to quickly deploy sterile insects outside of the dispersal facility range. Mass production and targeted dispersal of sterile flies remain critical components of an effective response.

USDA currently produces sterile flies for dispersal at the COPEG facility in Panama. USDA is also investing $21 million to support Mexico’s renovation of an existing fruit fly facility in Metapa — which will double NWS production capacity once complete. With ongoing support from technical experts in USDA’s APHIS, Mexico anticipates this sterile fly production to begin as soon as summer 2026.

NWS Flies Are Not in the U.S.

Rollins stresses there are no NWS flies in the U.S. She gave an update on the horse from Argentina that was found at the equine import quarantine facility in Florida with an open wound with larvae. She says once it was confirmed to have NWS, the animal was treated and remained in quarantine until it was reexamined and determined to be free of NWS.

Dr. Adis Dijab, DVM and veterinary services associate deputy administrator for USDA’s Animal and Plant Health Inspection Service (APHIS), gave an update on NWS in the cattle health and well-being committee during CattleCon. He explains Moore Air Base is the hub of the U.S. expansion for sterile NWS flies. He says the dispersal facility is operational and the production plant is scheduled to be built and fully online by 2027 — aiming for 300 million sterile flies per week.

He says the large‑scale production build‑out (the 300‑million‑per‑week plant) is still moving through contracting and construction. He anticipates awarding a construction contract in March or April.

On January 30, USDA announced a shift in its 100 million-per-week sterile fly dispersal efforts to reinforce coverage along the U.S.-Mexico border. While the sterile flies for this effort will initially be dispersed from the Tampico, Mexico, facility, USDA is prepared to quickly and strategically shift operations to the new Texas facility should there be a change in the location or new concentration of NWS cases in northern Mexico.

According to an announcement by USDA, the dispersal in Texas begins Feb. 9.

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