Screwworms are back. For ranchers, it is just the latest hit.

In March 2025, as the Trump administration effectively dissolved the U.S. Agency for International Development, a stop-work order shuttered a program dedicated to monitoring and containing of the New World screwworm — flesh-eating parasitic flies that can kill livestock — in Central America. 

A little more than a year later, the screwworm is back, and has been detected within the United States for the first time since its eradication in 1966 — the latest in a series of challenges pressuring American cattle ranchers, many of whom are concurrently facing drought, inflation and economic woes caused by the president’s foreign policy. 

Agriculture Secretary Brooke Rollins has sought to downplay the severity of the pest’s reemergence, but farmers fear the screwworm will mean yet another expense for their farms.

“Is it going to cost me money? Yes, it will cost me money,” said Scott Blubaugh, a cattle rancher and president of the Oklahoma Farmers Union. “It’s going to take a lot more labor, a lot more time inspecting those herds and monitoring those herds out there.”

Since the start of Trump’s second term, ranchers have absorbed hit after hit. Tariffs drove up the cost of farm equipment. A controversial trade agreement with Argentina flooded the U.S. market with beef trimmings, depressing domestic livestock values. And after U.S. strikes on Iran triggered the closure of the Strait of Hormuz, supply chain disruptions roiled global oil and fertilizer markets, making feed and transportation more expensive.

For decades, the U.S. released millions of sterilized screwworm flies weekly across Central America, which kept the insect’s population in check north of Panama’s Darién Gap. But in 2023, the flies began a steady journey north, getting within 70 miles of the U.S.-Mexico border by last September. 

On June 3, screwworms were detected in the umbilical cord of a three-week-old calf in Zavala County, Texas. Within days, more cases were reported across the state, and on June 7, the parasites were found in a dog in New Mexico that had recently crossed the southern border. 

The shuttered screwworm monitoring program was one of several similar projects run by the United Nations Food and Agriculture Organization that were cut early in Trump’s second term by the Elon Musk-led Department of Government Efficiency effort, alongside projects that tracked diseases such as avian flu.

The defunding has drawn fresh scrutiny from federal and state officials following the screwworm’s reemergence. During a Senate Agriculture Committee hearing Wednesday, Sen. Ben Ray Luján, D-N.M., pressed Rollins on the cuts; she maintained they have not affected the USDA’s response. 

Sid Miller, Texas’ outgoing Republican agriculture commissioner, has criticized the USDA’s handling of the crisis, alleging that as screwworm moved north from Panama to Mexico, the “USDA moved too slowly and relied solely on a partial solution that takes years to fully implement,” rather than deploying every tool at its disposal. Rollins has said Miller’s comments were “disturbing and disruptive,” and claimed they were “harmful” to the department’s mitigation efforts.

While screwworms do not pose a threat to food safety, they may drive up the domestic price of beef, which is already at its highest on record. American ranchers have fewer cattle today than at any point since 1951, and a screwworm outbreak will likely discourage farmers from expanding their herd sizes, according to David Anderson, an agricultural economist at Texas A&M University.