New World Screwworm has breached U.S. borders for the first time in nearly 60 years, sending shockwaves through the American livestock industry. USDA’s Animal and Plant Health Inspection Service confirmed the first domestic case on June 3, 2026. The detection occurred in a three-week-old calf in Zavala County, Texas. Federal and state officials launched an immediate emergency response. Agriculture Secretary Brooke Rollins called the outbreak a very serious threat to American livestock.
Background on New World Screwworm
Furthermore, the history of this parasite makes its return especially alarming for producers. The New World Screwworm is a parasitic fly whose larvae burrow exclusively into the living flesh of warm-blooded animals. It targets cattle, pets, wildlife, and rarely, people. In the 1960s, USDA successfully eradicated the pest from the United States using sterile fly releases. Since 2023, however, the parasite broke through containment barriers and spread northward through Central America and Mexico. By late 2024, cases emerged in Chiapas, Mexico, triggering urgent federal preparations.
Key Details of the New World Screwworm Outbreak
Notably, the case count escalated quickly after the initial detection. By June 9, 2026, USDA confirmed six total domestic animal cases. Those cases included four cattle, one goat, and one dog. USDA confirmed two additional cases on June 8 — a calf in La Salle County, Texas, and a dog in Andrews County, Texas. An isolated case also appeared in Lea County, New Mexico. Texas Governor Greg Abbott signed an emergency declaration on June 5, 2026. The state secured immediate federal funding from USDA to hire additional livestock inspectors and expand containment operations.
Industry Impact of New World Screwworm
Consequently, the outbreak hit an already strained cattle industry at the worst possible time. U.S. cattle herd counts currently sit at their lowest levels in decades. Beef prices already reached historically high levels in 2026 before this outbreak emerged. Analysts warn the New World Screwworm could cost the economy billions of dollars. Texas livestock producers alone stand to lose $1.8 billion if the pest reinfests the state. CNBC reported that the outbreak could add inflationary pressure on beef prices this summer. The National Cattlemen’s Beef Association, however, stressed that the U.S. beef supply remains safe and secure.
What Comes Next for New World Screwworm Containment
Meanwhile, USDA deployed its primary eradication weapon — sterile fly releases — along the Texas border. Officials dispersed dyed sterile fly pupae at ranches in the outbreak zone as early as June 11, 2026. However, the American Farm Bureau Federation warned that sterile fly supply presents a critical constraint. Current production facilities cannot meet the demands of an expanding outbreak. USDA appointed Texas cattleman John Bellinger as Senior Advisor for New World Screwworm Preparedness on June 8. Secretary Rollins called the response an all-of-administration effort. USDA also works closely with Mexico to improve surveillance and detection across the shared border.
Conclusion
Importantly, USDA reassures consumers that the food supply faces no threat from this outbreak. The New World Screwworm does not infest meat, fruits, vegetables, or other food products. Producers, however, face real and immediate economic danger. The American agriculture sector now watches closely as federal and state agencies race to contain the outbreak before it establishes a foothold. USDA urges all livestock producers near affected areas to inspect animals immediately for draining wounds, larvae, or eggs around body openings. Producers should report any suspected case to state animal health officials or USDA within 24 hours.
Related: New World Screwworm Returns to US Livestock
Originally reported by USDA APHIS. Analysis by the GardenScoop Editorial Team.
