A flesh-eating parasite’s reemergence in Texas after six decades isn’t just threatening to impose millions of dollars in losses on the cattle industry—it’s also causing a major rift between a MAGA diehard and the Trump administration over its response to the crisis.
The New World screwworm fly—a parasitic fly that lays its eggs in the open wounds of not only livestock like cattle, but also pets and humans in some cases—was discovered in Texas last week for the first time since 1966. Then on Monday, the United States Department of Agriculture (USDA) also reported the first case of the fly in neighboring New Mexico.
Once hatched, screwworm larvae feed on the living flesh of their host, potentially leading to infection, foul odors, and death, sometimes within a week if not treated properly. Before the screwworm fly was first eradicated in the 1960s, it led to between $10 and $20 million in losses for livestock producers per year, according to USDA estimates. As the pest threatens to return in full force to the U.S., the USDA has put millions toward reviving a tried and true approach to containing the pest—producing sterile, male screwworm flies, which are then released into affected areas to mate with females that produce infertile eggs. Because female flies only mate once in their life, this approach helps to stem its population growth. This strategy was key to eradicating the pest for the first time in the 1960s.
Yet, Texas agricultural commissioner and Trump loyalist Sid Miller has taken aim at the USDA’s approach. Miller, who lost a reelection bid in March despite an endorsement from President Donald Trump, tore into the department in a statement last week, saying “the USDA moved too slowly” and is relying on the “partial solution” of sterile insect release, instead of using all the tools at its disposal, which includes a strategy that employs bait and targeted pesticides to kill the pests.
Miller criticized the sterile insect approach as an ineffective,“100-year-old technology.” He said the sterile flies being released are both male and female and are mating with each other instead of with wild flies.
“The sterile fly just mates with the other sterile females, so it doesn’t work,” he said in a Monday interview with News Nation, before blaming the affordability crisis at the supermarket on the flies and not as one of the results of the Iran war or Trump’s tariffs on meat-exporting countries like Brazil “You can look for higher beef prices because of the USDA,” he added later in the interview.
While the sterile insect release method relies primarily on sterile males reproducing with wild females, sterile male and female flies are often released at once for practical reasons. Some studies on the sterile insect technique as a means of managing fruit flies have shown a negligible difference when males and females are released together compared to males alone.
Flawed by design
Because the USDA has set up a quarantine zone to contain the spread of the screwworm, Miller also argues farmers are less likely to report the pest if they find it.
“I urge all Texas producers to report suspected New World screwworm cases to their veterinarian, USDA, TAHC, or the Texas Department of Agriculture. But farmers and ranchers have told me current USDA and TAHC quarantine policies discourage reporting. Those policies should be revised,” he said in a statement to Fortune.
Asked about Miller’s comments during a Monday press conference, the U.S. Secretary of Agriculture and USDA chief Brooke Rollins called Miller’s comment a “dangerous suggestion,” adding that it was “a very unserious comment from a perhaps unserious [agriculture] commissioner with just a few months left.”
Miller shot back at Rollins’ remark in a statement to Fortune.
“Secretary Rollins’ name-calling is disappointing. This threat is too serious for petty politics. My team and I will stay focused on protecting Texas agriculture, not trading insults. We led the fight against New World screwworm from the start, and we’ll keep leading it,” he said.
The USDA did not immediately respond to Fortune’s request for comment.
Miller’s rare critique sets up a clash between the Trump administration and a vocal, Trump-backed politician in a Republican-controlled state, as well as growing fissures within the MAGA movement.
Miller is, by seemingly all accounts, a MAGA stalwart. He has previously criticized members of the Republican party in the Texas legislature as “RINOs” (Republican in Name Only) for allegedly undermining party priorities and earned President Trump’s endorsement earlier this year as he sought reelection. He later went on to lose his reelection bid to a candidate backed by the Texas governor, Greg Abbot.
“President Trump described me as a MAGA Warrior who has stood with him from the very beginning,” wrote Miller on the endorsements page of his website.
Real economic losses
In Texas, this tension between dedicated MAGA supporters and the Trump administration comes with high stakes thanks to the threat of a broader screwworm infestation. Although the screwworm fly doesn’t pose a threat to food safety, according to the USDA, it does threaten ranchers and producers in Texas, which alone account for about 14% of U.S. cattle production.
Texas A&M estimates that if the fly manages to reestablish itself in the U.S., this would lead to losses of $2.1 billion in the cattle industry and $9 billion to the hunting and wildlife industry just in Texas.
Miller has said he has repeatedly suggested to Rollins that the USDA should employ the “Screwworm Adult Suppression System,” which uses bait and targeted pesticides to kill screwworms. Yet, the USDA prefers the release of sterile specimens partly because it “is safe, environmentally friendly, and offers a sustainable, non-toxic alternative to chemical pesticides,” according to a factsheet. It is also considering other methods to control the spread of screwworm, including potentially releasing a genetically engineered, male-only strain of the fly into the environment.
For now, the USDA is doubling down on the sterile insect technique. Last year, it put $21 million into converting a fruit fly facility in Tampico, Mexico to produce more of these sterile flies. It has also put $750 million into a similar factory in southern Texas and opened a new center for dispersing these flies in the same region earlier this year.
Yet, these efforts aren’t enough for Texas agricultural commissioner and Trump loyalist Sid Miller, who urged the USDA to act faster as the screwworm threat spreads in his state and beyond.
“We’ve seen detections in four counties and two states. This should set off alarm bells across the country,” he wrote in a statement. “Every day we delay gives this pest another opportunity to spread.”
