Story perspectives

Texas Screwworm Outbreak Triggers 12-Mile Quarantine

6/4/2026

Summary

Story summary

Screwworm infestation was found in a three-week-old calf in Zavala County, Texas, prompting a 12-mile quarantine.
USDA confirmed the parasite and sent the sample to the National Veterinary Services Laboratories.
USDA activated sterile-fly releases, runs 8,000 border traps and, despite over 26,000 Mexican cases, said risk to U.S. livestock remains very low.
Texas Agriculture Commissioner Sid Miller criticized the response and asked President Donald Trump to deploy the Screwworm Adult Suppression System.

History

Historical Context

The sterile-insect technique, devised by Edward F. Knipling and Raymond C. Bushland and adopted by the USDA in 1958, eliminated the New World screwworm from the southern United States by 1966 after releasing more than 94 billion sterile flies. A 2026 infestation in Zavala County has prompted Texas Commissioner Sid Miller to ask President Trump for a repeat of that large-scale release, echoing the historic program.

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Story summary

Screwworm infestation was found in a three-week-old calf in Zavala County, Texas, prompting a 12-mile quarantine.
USDA confirmed the parasite and sent the sample to the National Veterinary Services Laboratories.
USDA activated sterile-fly releases, runs 8,000 border traps and, despite over 26,000 Mexican cases, said risk to U.S. livestock remains very low.
Texas Agriculture Commissioner Sid Miller criticized the response and asked President Donald Trump to deploy the Screwworm Adult Suppression System.

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