The U.S. Department of Agriculture (USDA) and Texas Agriculture Commissioner Sid Miller are feuding over how to contain the New World screwworm fly, a flesh-eating parasite confirmed in Texas on 5 June 2026 and in neighboring New Mexico four days later.
The parasite’s return after six decades has reignited debate about the federal government’s reliance on the sterile insect technique—releasing lab-reared, non-reproductive flies to collapse wild populations. The dispute highlights how pest management decisions can reverberate through the broader farm economy, an issue S&N Global regularly examines in its Business coverage.
The screwworm fly (Cochliomyia hominivorax) lays eggs in open wounds of cattle, wildlife, pets and, on rare occasions, humans. Hatched larvae consume living tissue, generating infection, severe odor and, if untreated, death within a week. Before eradication in the late 1960s, the fly cost U.S. livestock producers an estimated $10 million to $20 million annually, according to USDA historical data.
Political pushback on a legacy method
Miller, a staunch supporter of former president Donald Trump, called the USDA response “too slow” and labeled sterile-fly releases “100-year-old technology” in a 7 June statement. He argues the agency should also deploy bait stations and targeted pesticides, known as the Screwworm Adult Suppression System.
“The sterile fly just mates with the other sterile females, so it doesn’t work,” Miller told News Nation on 9 June.
USDA Secretary Brooke Rollins dismissed that critique in a 10 June press conference, calling Miller’s position “a dangerous suggestion.” Miller countered that quarantine rules discourage ranchers from reporting new cases, potentially masking the insect’s spread.
The clash is unusual inside Republican politics. Miller lost his March 2026 re-election primary despite a Trump endorsement, underscoring shifting intraparty alliances as biosecurity becomes an economic flashpoint.
Economic stakes for cattle country
Texas accounts for roughly 14 percent of U.S. cattle production. Texas A&M University calculates that a permanent screwworm foothold could drain $2.1 billion from the state’s cattle sector and $9 billion from hunting and wildlife activities. “Every day we delay gives this pest another opportunity to spread,” Miller warned in a 10 June release.
The USDA says the sterile insect technique is safe, environmentally friendly and historically effective because female screwworms mate only once. To scale up, the agency invested $21 million in 2025 to convert a fruit-fly facility in Tampico, Mexico, into a screwworm-fly factory and committed $750 million to a new production center in southern Texas, opened earlier this year.
Although the method ideally releases only sterile males, both sexes are often dispersed for logistical reasons. A 2024 peer-reviewed study on fruit flies, cited by USDA officials, found negligible differences in population suppression when males and females were released together.
Additional countermeasures are under review, including a genetically engineered male-only strain, but no timeline has been set. For now, tens of millions of sterile flies are being aerially distributed across the quarantine zone that straddles the Texas-Mexico border.
The stakes extend beyond ranchers. Higher treatment costs, animal losses and transport restrictions could tighten beef supply chains already strained by tariff disputes and fertilizer price spikes linked to the Iran war, factors Miller also cites in blaming rising food prices.
Two sentences capture the key facts:
- The U.S. Department of Agriculture confirmed the first Texas case of New World screwworm on 5 June 2026, the agency’s first detection since 1966.
- Texas A&M University estimates that re-establishment of the parasite could remove $2.1 billion from the state’s cattle industry and $9 billion from wildlife revenue.
The USDA has not indicated when it might widen its toolkit. For now, the agency insists that rapid reporting, strict quarantine and continuous sterile-fly releases are the best defenses against a pest that once ravaged North American herds.
Whether that stance can withstand mounting political pressure from within the GOP will determine not only the course of the outbreak, but also the resilience of a cattle industry worth more than $70 billion nationwide.
