The livestock industry is on high alert as the New World screwworm—an invasive parasitic fly capable of killing untreated animals—continues to spread north through Mexico.
Escalating Outbreak in Mexico
As of mid-September, Mexico has reported 6,703 confirmed cases of screwworm infestations since the outbreak began in November 2024. This represents a 32% increase from the previous month’s tally of 5,086 cases. The majority of these cases—5,258—were found in cattle, underscoring the parasite’s devastating impact on the beef sector.
- Chiapas, bordering Guatemala, remains the hardest-hit state with 3,474 cases, up from 2,875 in August.
- Oaxaca saw cases rise to 744 (from 453).
- Veracruz nearly doubled, with 476 cases compared to 252 last month.
- For the first time, Puebla—about 80 miles from Mexico City—recorded five confirmed cases.
Critically, on September 21, Mexico confirmed a screwworm case in Nuevo León, a state that directly borders Texas. Authorities said the infected animal was treated immediately to prevent further spread.
The northward concentration of the outbreak has strained relations between the U.S. and Mexico. Washington has criticized Mexico’s containment efforts, and U.S. cattle imports from Mexico have been largely halted since May.
U.S. Precautions and Investments
Recognizing the mounting threat, the U.S. Department of Agriculture (USDA) announced in August a $750 million plan to build a sterile fly production facility in Edinburg, Texas, at Moore Air Base. Once completed, the plant will be capable of producing 300 million sterile screwworm flies per week. These sterile insects reduce the wild population by interrupting reproduction, a method that helped eradicate screwworm in the U.S. during the 20th century.
The facility is expected to take two to three years to build. In the meantime, USDA will invest an additional $100 million into new technologies, enhanced surveillance, and expanded border patrol operations. Mounted officers are being deployed to monitor cattle and wildlife in high-risk areas.
Potential Impact on the Beef Industry
Texas Governor Greg Abbott has called the situation a “serious threat” that could “truly crush the cattle industry” if the parasite crosses into the U.S. An outbreak would further tighten an already strained cattle supply, putting additional pressure on record-high U.S. beef prices.
USDA has also committed resources to a new sterile fly plant in Mexico, slated to open in 2026, and continues supporting efforts at the Panama facility, which currently produces 100 million sterile flies weekly. Experts estimate at least 500 million sterile flies per week are needed to push the outbreak back south.
Why This Matters for Wagyu Producers
For Texas Wagyu ranchers, the implications are twofold:
- Animal health risk – Wagyu, like all cattle, are highly vulnerable to screwworm infestations, which can be fatal if untreated. Vigilance in herd management is essential.
- Market pressures – Any disruption to cattle supply or restrictions on trade could drive beef prices even higher, influencing both domestic sales and export opportunities for premium Wagyu beef.
Moving Forward
The Texas Wagyu Association encourages all members to:
- Stay informed through USDA and Texas Animal Health Commission updates.
- Monitor herds closely for signs of screwworm infestation.
- Support coordinated efforts to safeguard the U.S. cattle industry from this serious threat.
With careful planning and proactive measures, the industry can remain vigilant and prepared against the resurgence of a parasite last seen in U.S. herds nearly 50 years ago.
This article summarizes information from online market research reports. The Texas Wagyu Association is sharing this for informational purposes only and makes no guarantees regarding the accuracy of the projections or claims presented in the original report.