Samples from Texas Cattle Ranch Tested for Possible Screwworm Infestation

Samples from two calves on a La Pryor, Texas cattle ranch were sent to a federal lab in Iowa for screwworm testing on June 3, 2026, after collection on June 2, 2026. The USDA confirmed a screwworm case 25 miles south of the Texas border in Coahuila state on June 2, 2026. A U.S. outbreak could cause $1.8 billion in damage to Texas' economy alone. No confirmed case exists in Texas as of June 3, 2026.

Texas ranch screwworm testing

• ▪One of the suspected screwworm infestations on the La Pryor, Texas ranch was detected in an umbilical cord wound of a calf
• ▪Texas Representative Don McLaughlin stated on June 3, 2026, that the suspected screwworm infestation in La Pryor, Texas is unconfirmed
• ▪The Texas Animal Health Commission stated on June 3, 2026, that there has been no confirmed case of New World screwworm in Texas
• ▪Samples of an unconfirmed screwworm infestation from a cattle ranch in La Pryor, Texas, were sent to a federal government lab in Iowa for testing on June 3, 2026
• ▪The samples from the La Pryor, Texas ranch were taken from two calves on June 2, 2026

Cattle futures market impact

• ▪Widespread market chatter about the suspected screwworm case in La Pryor, Texas hung over cattle futures on June 3, 2026
• ▪Market players believe a screwworm infestation in the U.S. could reduce demand for beef from consumers nervous about the flesh-eating pest
• ▪Cattle futures traders have long been sensitive to threats of New World screwworm
• ▪Market players believe a screwworm infestation in the U.S. would be bullish in the long term by reducing the U.S. cattle supply

USDA prevention efforts

• ▪Washington has kept its border closed to cattle imports for more than a year in an effort to prevent the screwworm parasite from reaching U.S. border states
• ▪The United States has spent millions of dollars to slow the screwworm's advance through Mexico by investing in sterile fly production facilities, expanding trapping efforts, and increasing livestock surveillance
• ▪The U.S. Department of Agriculture confirmed a screwworm case 25 miles south of the Texas border in Coahuila state on June 2, 2026
• ▪The U.S. Department of Agriculture is leading the screwworm prevention effort in the United States

Screwworm parasite characteristics

• ▪Screwworms are parasitic flies whose females lay eggs in wounds on any warm-blooded animal
• ▪Once screwworm eggs hatch, hundreds of screwworm larvae use their sharp mouths to burrow through living flesh, eventually killing their host if left untreated
• ▪The New World screwworm parasite has been moving north through Mexico for more than a year as of June 2026

Economic damage projections

• ▪A screwworm outbreak in the U.S. would likely raise U.S. beef prices by shrinking the U.S. cattle supply
• ▪An outbreak of screwworm in the U.S. could cause $1.8 billion in damage to Texas' economy alone

Perspective of Cattle futures market players

• ▪Market players believe a screwworm infestation in the U.S. would be bullish in the long term by reducing the U.S. cattle supply
• ▪Market players believe a screwworm infestation in the U.S. could reduce demand for beef from consumers nervous about the flesh-eating pest

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