At a Glance
- First Mexican screwworm case reported in Tamaulipas on Dec. 27.
- Texas Agriculture Commissioner urges expanded use of sterile flies.
- Threat to Texas livestock remains despite progress in slowing spread.
- Why it matters: Livestock producers must stay alert to protect herds from a parasitic fly that can cause severe damage.
Texas Agriculture Commissioner Sid Miller issued a warning to livestock producers after Mexican officials confirmed the first New World screwworm case in the state of Tamaulipas. The detection, reported on Dec. 27, marks the northernmost case and underscores the ongoing threat to Texas herds.
Screwworm Detection in Tamaulipas
The National Service of Agro-Alimentary Health, Safety, and Quality (SENASICA) reported a case in a calf about 197 miles south of the U.S.-Mexico border. It is the first instance in Tamaulipas and the northernmost in Mexico. Screwworms are parasitic flies that can cause severe harm to livestock and wildlife.
Response and Recommendations
Miller highlighted progress in slowing the pest’s spread but stressed that eradication hinges on expanding the sterile insect technique. He said:
Sid Miller stated:
> “Dollars don’t kill screwworms, sterile flies do,”

The federal and Mexican authorities have helped contain the outbreak, and Miller praised USDA Secretary Brooke Rollins for launching a five-point plan earlier this year aimed at strengthening the response. Producers should monitor updates from the Texas Department of Agriculture and USDA’s Animal Plant Health Inspection Service.
- Check the Texas Department of Agriculture website for updates.
- Follow USDA APHIS updates.
- Report any suspected cases promptly.
Key Takeaways
- First screwworm case in Tamaulipas, northernmost in Mexico.
- Sterile fly program is critical for eradication.
- Producers must stay vigilant and report new cases.
With the sterile fly program at the center of containment efforts, Texas producers must remain vigilant as the threat to livestock continues.

