In the dusty heart of Texas, a sense of unease is growing among ranchers and agricultural officials alike. The source of their anxiety? The flesh-eating New World screwworm, a parasitic fly that, after decades of absence, is now edging perilously close to the U.S. border. With the pest’s relentless march northward from Central America, the United States Department of Agriculture (USDA) and Texas authorities are scrambling to mount a defense—one that will test the limits of science, logistics, and sheer grit.
On August 15, 2025, USDA Secretary Brooke Rollins unveiled a sweeping plan to spend up to $750 million building a state-of-the-art sterile fly production facility in Edinburg, Texas. The facility, to be co-located with a dispersal center at Moore Air Base, is expected to churn out an astonishing 300 million sterile screwworm flies per week, according to Reuters. These sterile flies, when released, mate with wild screwworms, effectively reducing the population by ensuring that future eggs never hatch. “It’s a tactical move that ensures we are prepared and not just reactive,” Rollins said at a press conference alongside Texas Governor Greg Abbott.
But time is not on their side. The screwworm, still roughly 370 miles south of Texas as of mid-August, has already sparked alarm bells. Texas Commissioner of Agriculture Sid Miller described the pest in no uncertain terms: “Screwworm is like something out of a horror movie. It’s a flesh-eating maggot. I mean, it couldn’t get any worse than that.” Miller’s urgency is echoed by ranchers who remember the devastation of the 1970s outbreak, when tens of thousands of cattle across six states were infested, costing tens of millions of dollars to contain.
The sterile fly method isn’t new. In the 20th century, the U.S. eradicated screwworms by dropping boxes of sterile flies from planes over hot zones. The Mission, Texas plant, built in 1962, produced 96 trillion flies before being decommissioned in 1981. Now, with the threat returning, the USDA is resurrecting this approach. Yet, the scale of today’s challenge dwarfs past efforts. As Dr. Thomas Lansford, assistant state veterinarian at the Texas Animal Health Commission, told Reuters: “It’s an overwhelming situation at this point. Screwworm is obviously doing well in Mexico, and they’re up against the same challenges we are.”
Indeed, current production capacity lags far behind what’s needed. The Panama facility, a world-renowned biological center, breeds up to 100 million sterile flies per week. But the USDA estimates that 500 million need to be released weekly to push the pest back south. Commissioner Miller puts the number even higher—600 million per week. “We only have 100. So it’s going to take three, probably four years to ramp up production facilities to get to that number. We can’t wait four years,” Miller warned in an interview with Big Country News. The urgency is compounded by the fact that the new Texas facility will take two to three years to build, and a similar plant in Metapa, Mexico, is still a year from completion.
While the sterile fly strategy remains the backbone of eradication efforts, Texas is hedging its bets with a suite of new technologies. Miller revealed that the state is developing a fly bait capable of killing 90% of screwworms and is collaborating on a vaccine-like inoculation that alters blood proteins in livestock, making them inhospitable to the larvae. There’s also Ivermectin, a drug that gained notoriety during the COVID-19 pandemic, which Miller says is “very effective. It’ll prevent or cure anybody or any animal that has it. Just give them some ivermectin, it knocks it right out.” However, none of these tools are ready for immediate deployment, and the clock is ticking.
The stakes couldn’t be higher. According to the USDA, an outbreak could inflict $1.8 billion in damage to Texas’s economy alone. Miller cited even more dire projections: up to $20 billion in losses for the cattle industry and $30 billion annually across all livestock species. With U.S. beef prices already at record highs, the prospect of further supply shocks is a nightmare scenario for ranchers and consumers alike.
Veteran ranchers like Kip Dove, who lived through the 1970s outbreak, are haunted by memories of sick and dying cattle, the stench of rotting flesh, and the exhausting, low-tech treatments—scraping maggots from wounds and spraying insecticide. “The smell is bad, and some of the wounds are horrific. You have humongous holes in these animals teeming with worms,” Dove recalled to Reuters. Today, he fears the industry lacks the skilled labor needed for such grueling work. “There are no cowboys anymore,” said Isaac Sulemana, a rancher and attorney in Sullivan City, Texas. “Preventing deaths during a screwworm outbreak requires ranchers to adopt a punishing routine of monitoring every single head of cattle every single day.”
The threat extends beyond cattle. The multi-billion-dollar hunting industry is also at risk, as wildlife infested with screwworms are essentially untreatable and often die unseen in the brush. “This might be the worst biological outbreak that we’re facing in our lifetime,” said Freddy Nieto, manager at El Sauz Ranch in South Texas.
Meanwhile, on the other side of the border, the outbreak is intensifying. In Chiapas, Mexico, screwworm cases are rising by about 10% each week, with nearly 50,000 cases reported from Panama to Mexico, according to the Panama-United States Commission for the Eradication and Prevention of Screwworm. Increased migration of cattle and people from Central America is believed to be fueling the outbreak, prompting Mexican authorities to review livestock crossings and launch campaigns urging producers to vigilantly inspect their herds.
Back in Texas, the USDA has halted cattle imports from Mexico and deployed “Tick Riders”—inspectors on horseback—to patrol the border and treat cattle and horses for screwworms. The Texas Department of Agriculture has scattered 100 screwworm traps along the border and is urging anyone who suspects an infestation to call their hotline for testing.
Despite the daunting math and logistical hurdles, officials remain determined. As Rollins put it, “All Americans should be concerned, but it’s certainly Texas and our border and livestock-producing states that are on the frontlines of this every day.” Ranchers, too, are preparing for the worst, stockpiling insecticides and dusting off old bottles of screwworm medicine. Warren Cude, a third-generation West Texas rancher, summed up the mood: “We’re repeating history after 50 years. We didn’t learn from the first time and we let those facilities go and now we’re having to do everything again to combat something we eradicated 50 years ago.”
For Texas and the nation’s livestock industry, the coming months will be a test of preparation, innovation, and resolve in the face of a relentless biological foe.