Along with most Southern cattle producers, Southern Ag Today has been tracking the movement of the New World Screwworm (NWS). An article last November (linked here) provided a history of NWS and discussed implications of import restrictions on feeder cattle from Mexico. A second article (linked here) continued the discussion as the U.S. closed and re-opened the border to Mexican cattle throughout the spring and summer.
Earlier this week, an NWS case was detected 70 miles south of the Texas border in Nuevo Leon, Mexico, approximately 370 miles closer than the previous northernmost case detected in Veracruz, Mexico in July. As the threat of NWS reaching the U.S. grows, the need for eradication efforts and producer preparedness grow more urgent. Last year, the USDA estimated an NWS outbreak would result in a $732.6 million loss to Texas producers and a $1.8 billion loss to the Texas economy (APHIS, 2024). Losses for producers would come from animal deaths, decreased production, additional labor and vehicle costs for animal inspection and treatment, and additional medication and insecticide costs. Additionally, an NWS outbreak may prompt producers to make production practice changes to minimize NWS infestations. Recall, NWS cause harm by burrowing into open wounds of live animals. To minimize open wounds, producers may need to skip standard practices like dehorning, castrating, branding, and ear-tagging. They may also alter calving season to avoid calving during warm months when the NWS is more prevalent. The effects on marketing calves under these conditions is unknown.
The best and highly supported path forward is eradication. To that end, in June USDA laid out a 5-pronged plan to address NWS (USDA, 2025a). In summary, the plan included:
- Prevention of NWS spreading in Mexico through enhancements to sterile fly production in Mexico; improvements of Mexico’s NWS surveillance; an audit of Mexico’s animal health controls; and limitations on movement of animals.
- Protecting the U.S. border by collaborating with border personnel to gather strays, intercept illegally introduced livestock, and monitor wildlife; preparing laboratories to test for NWS; and continuing live animal inspections at ports of entry.
- Preparing for an outbreak through emergency management plans; training of federal and state responders; and stockpiles of treatment supplies.
- Moving eradication efforts forward by:
- Building an $8.5 million sterile insect dispersal facility at Moore Air Base in South Texas – to be completed by the end of 2025.
- Exploring the possibility of a domestic sterile fly production facility.
- Investing $21 million in the renovation of Mexico’s sterile insect facility – to be completed in 18 months.
- Planning for the future by exploring new treatments and preventatives; improving sterile insect production and technology; and strengthening partnerships with states and land grant universities.
In August, Secretary Rollins announced that USDA would be building on the 5-prong plan, in part, by investing $100 million to identify new innovations for tackling NWS and that USDA will construct a sterile fly production facility in Edinburg, TX, at Moore Air Force Base (USDA, 2025b).
Animal and Plant Health Inspection Service (APHIS). 2024. New World Screwworm, Ready Reference Guide – Historical Economic Impact. https://www.aphis.usda.gov/sites/default/files/nws-historical-economic-impact.pdf
USDA. 2025a. New World Screwworm Domestic Readiness and Response Policy Initiative. https://www.usda.gov/sites/default/files/documents/nws-visit-policy-brief.pdf
USDA. 2025b. USDA Announces Sweeping Plans to Protect the United States from New World Screwworm.https://www.usda.gov/about-usda/news/press-releases/2025/08/15/usda-announces-sweeping-plans-protect-united-states-new-world-screwworm
Graff, Natalie. “Threat Looms and Urgency Grows as New World Screwworm Inches Closer to the Texas-Mexico Border.” Southern Ag Today 5(39.4). September 25, 2025. Permalink
