US‑Mexico Open Sterile Fly Facility to Combat Screwworm Outbreak
The United States and Mexico have inaugurated a new sterile‑fly production facility in Metapa, a town near Mexico’s southern border, as part of a joint effort to halt the spread of the New World screwworm that is threatening cattle herds across North America. The facility is expected to produce up to 100 million sterile flies per week once it reaches full capacity. Production will start at 30 million sterile pupae per week in July, increase to 60 million in August, and achieve the 100 million‑per‑week target by November. The sterile insects will be distributed by air to affected regions in both countries.
When combined with an existing plant in Panama, weekly output will rise to roughly 200 million sterile flies, and additional facilities are planned to further boost production. The sterile insect technique, which previously eradicated the screwworm from North America decades ago, involves releasing sterilized male flies that mate with wild females, thereby preventing the next generation of the parasite.
The screwworm has re‑emerged as a major threat; thousands of infections have been reported in Mexico since 2024, and U.S. authorities confirmed the first domestic livestock infections earlier this month—the first such cases in about 50 years. U.S. Agriculture Secretary Brooke Rollins said the two nations had successfully eliminated the pest before and expressed confidence that the current initiative would achieve the same result. U.S. Ambassador Ronald Johnson announced an additional $84 million in funding to contain the outbreak and warned that a widespread infestation could cost the U.S. agriculture sector more than $700 million annually.
In parallel, the United States is constructing a separate sterile‑fly production facility in Texas, which is not expected to become operational until late 2027. The joint initiative reflects broader U.S.–Mexico cooperation on agricultural and cross‑border issues, aimed at protecting livestock production and preserving agricultural trade between the two countries.