Metapa Fly Plant Gives U.S., Mexico Needed Weapon Against Screwworm — But Full Containment Still Depends on Speed
Rollins says USDA has invested $1.3 billion, expanded its screwworm workforce by 1,000% and opened the Chiapas facility as part of a broader five-point plan to protect U.S. ranchers
The U.S. and Mexico opened the sterile New World screwworm fly production facility in Metapa, Chiapas, on Saturday, marking the most significant near-term capacity gain yet in the fight to keep the flesh-eating parasite from spreading deeper into Mexico and the United States. The facility, located near Mexico’s southern border, is designed to produce sterile flies that can be released to mate with wild flies, interrupt reproduction and gradually suppress the pest. Reuters reported the plant is expected to produce up to 100 million sterile flies per week, while experts cautioned that even this added capacity may not be enough by itself to fully eradicate the pest.
USDA Secretary Brooke Rollins used the opening to frame the facility as both a scientific milestone and proof that the Trump administration’s screwworm strategy has moved from planning to execution. At the ceremony, she said, “Our countries have beaten this before,” and added, “We will beat the New World screwworm again, sooner than anyone would have thought,” according to Reuters.
Rollins went further in a post on X (link), saying the opening was tied directly to the administration’s earlier response plan. “On June 18th of last year, our Trump USDA launched a bold 5-point action plan to defeat New World screwworm and protect our great American ranchers,” she wrote. USDA’s June 18, 2025, announcement did launch a “sweeping five-pronged plan” to detect, control and eliminate New World screwworm, including the opening of a South Texas sterile fly dispersal facility and investments in additional production capacity.
Rollins said the pest’s northward movement had been predictable and dangerous. In her X post, she wrote that New World screwworm had been “fully eradicated from the United States” since 1966, then “breached the Darien Gap in 2021, through Central America in 2022, and made its way northward and into Mexico through 2023 and 2024.” She said “all models showed it reaching the U.S. by Summer 2025.” That point is central to USDA’s defense of its response: the agency argues that border closures, Mexico-based staffing and production investments bought time for the U.S. cattle sector before the pest reached domestic animals.
The timing has become more urgent since APHIS confirmed New World screwworm in a Texas calf in Zavala County on June 3, the first confirmed U.S. livestock detection in the current outbreak. USDA said then that the larvae were found in the umbilical area of a three-week-old calf and that animal health officials were moving quickly to protect livestock and wildlife.
Rollins’ X post gives the administration’s clearest accounting of what it believes that delay achieved. “We were able to hold it off for a full year by closing the ports and surging USDA staff into Mexico, which allowed us to prepare, build, contain and partner,” she wrote. She said that as part of the five-point plan, USDA began building a “Massive 22,000 square ft facility in Metapa, Mx” eleven months ago to increase sterile fly capabilities.
That claim is important politically and operationally. The U.S. cattle industry has been frustrated by border disruptions, especially the halt or restriction of Mexican live cattle imports, but USDA’s argument is that those disruptions were necessary to slow the pest and buy time for facilities like Metapa. The U.S. border has been mostly closed to Mexican live cattle since May 2025, disrupting a trade flow that had supplied more than 1 million animals annually to U.S. feedlots.
The Metapa ramp-up will now be closely watched. Rollins wrote that “today represents a major milestone” and said USDA expects “within 8 weeks” to have 30 million flies, “in 12 weeks” to have 50 million flies and “by this Fall an additional 100 million flies to deploy.” USDA’s facilities page has said the Metapa conversion is expected to add 60 million to 100 million sterile New World screwworm flies per week once complete, on top of production from Panama.
The capacity math still argues for caution. The existing Panama facility produces around 100 million sterile flies per week, and Metapa may eventually add another 100 million. But the earlier eradication campaign operated at much higher volumes, and USDA has cited the need to build toward roughly 400 million to 500 million sterile flies per week for an effective large-scale response. Reuters reported that, before the new investments, the only North American production source was Panama and that USDA viewed the U.S. need as 400 million to 500 million sterile flies per week.
Rollins also pointed to a potentially important production improvement, saying she and Mexican officials discussed “the importance of integrating the new NOVO fly into production as soon as possible.” She wrote that the new fly “will double our 100 million weekly sterile flies within months.” If that timetable holds, the Metapa facility could become more than a stopgap; it could become a force multiplier before the larger U.S. production facility in Texas comes online in 2027
Even so, the Texas plant remains the critical longer-term piece. USDA broke ground this year on the Moore Air Base sterile fly production facility in Edinburg, Texas, which is expected to give the U.S. domestic production capacity rather than relying primarily on Panama and Mexico. USDA has said the Texas facility is intended to begin with 100 million sterile flies per week and ultimately reach 300 million per week.
Rollins’ X post also emphasized the scale of federal spending. She thanked Secretary of State Marco Rubio, the State Department and U.S. Ambassador Ronald Johnson, saying they announced “an additional $84 million in funding to expand fly production even more for our American producers.” She added: “So far we’ve invested $1.3 billion, expanded our New World screwworm workforce by 1,000%, and launched the largest response effort in decades.”
For producers, the importance of that investment is straightforward: the U.S. cattle herd is already tight, feeder cattle supplies remain constrained and any widening of screwworm quarantines could further complicate livestock movement, feedlot placements and cross-border trade. A major outbreak would not only threaten animals directly; it would also bring inspection costs, movement controls, treatment costs and market uncertainty. The most damaging scenario would be a series of scattered detections that force broader surveillance zones before sterile fly capacity is large enough to suppress the pest quickly.
The broader political message from the ceremony was cooperation. Mexican President Claudia Sheinbaum said the facility showed that the U.S. and Mexico can cooperate on technical problems while respecting sovereignty. Rollins closed her X post on the same theme: “We’ve beaten New World screwworm before through strong cooperation — and together, we’ll do it again.”
Bottom line: Metapa is a real and badly needed operational gain, but it is not the end of the screwworm risk. It gives USDA and Mexico more capacity to push the pest south and defend the border, and Rollins is presenting it as proof that early action bought time. But until Metapa reaches full output, the NOVO fly integration is proven at scale and the Texas facility is operating, the U.S. cattle sector remains in a vulnerable transition period. The fight has shifted from whether sterile fly capacity can be expanded to whether it can be expanded fast enough.
