America's Beef Farmers Can't Catch a Break

The New World screwworm has reached United States soil for the first time in six decades, federal officials confirmed Wednesday.

It’s the latest blow to an American cattle industry already under historic strain from trade disputes, record-low herd sizes, and a string of policy decisions tied to the Trump administration.

The U.S. Department of Agriculture confirmed a case in a 3-week-old calf in La Pryor, Texas, roughly 50 miles from the Mexican border. Texas State Veterinarian Bud Dinges imposed a 12-mile quarantine zone covering much of Zavala County and part of neighboring Uvalde County, prohibiting the movement of any warm-blooded animal without inspection.

Cattle producers in the affected region are calling on President Donald Trump to declare a national emergency, arguing that local officials on the front lines are not receiving adequate federal or state support.

What Is New World Screwworm?

Derrell Peel, an agricultural economist at Oklahoma State University, said, “It does horrific damage, and it is an extremely costly thing to manage and get rid of.”

The New World screwworm fly is unlike most insects:

• Its larvae eat live flesh rather than dead material, burrowing into open wounds on any warm-blooded animal, including livestock, wildlife, pets, and occasionally humans.
• A female mates only once in her monthslong life, which is also the key to controlling her.

Jennifer Koziol, an associate professor of food animal medicine and surgery at Texas Tech University School of Veterinary Medicine, said the threat extends beyond livestock. “We would be remiss to forget that this is a One Health concern and that humans can become infected with New World Screwworm,” she said, adding that wound care becomes “critically important” and calling on the Centers for Disease Control to confirm all human cases.

Does It Cause Food Issues?

U.S. Agriculture Secretary Brooke Rollins stressed the pest poses no food safety risk.

“This pest does not cause a food safety issue,” she said. “This is not a disease, it is not a virus.”

Animals treated early enough can make a full recovery, she added.

First Case in Texas Since 1966 Thanks to Breeding Technique

The pest was an annual scourge of cattle ranchers across the southern United States from at least the 1930s until the 1960s, when the USDA eradicated it through the Sterile Insect Technique: breeding sterile male flies by the millions and dropping them from planes so that wild females, upon mating, produce eggs that never hatch.

The U.S. confirmed its last Texas case in 1966.

The pest was contained in Panama until late 2024, when it began moving north at an accelerating pace through Central America and into Mexico.

“There are many challenges in this containment and eradication program,” Phillip Kaufman, a professor of entomology at Texas A&M University, said in an interview with Newsweek. “Producing sufficient numbers of sterile flies and getting them released in the correct places and at the right time is critical. If the flies move further north than the isthmus in southern Mexico, it becomes more and more challenging to contain them.”

Cattle Industry Pressurized Before the Fly Arrived

The confirmation comes at one of the worst possible moments for U.S. cattle producers.

• The American cattle herd is at 86.2 million head as of the latest USDA count, its lowest level since 1951, the result of years of drought, high feed costs, herd liquidation, and ongoing market disruptions.
• More than 79 percent of the beef cow herd in the 26 largest cattle-producing states is currently affected by drought.
• Beef production has fallen for several consecutive years, driving both cattle and beef prices to record highs.

Colin Woodall, CEO of the National Cattlemen’s Beef Association, said the industry was already buckling before the fly arrived. “The challenges facing cattlemen and women have led us to the smallest domestic herd we’ve had since the 1940s,” he said. “Drought, rising input costs and a lack of agricultural labor are all compounded by the arrival of New World Screwworm.”

Woodall added that the pest’s arrival had exposed strains that go beyond equipment and funding: producers would be fighting it “at a time when we have a shortage of large animal veterinarians and less labor available to detect flies and their larvae.”

The supply crunch has been compounded by:

• A February 2026 executive order expanding the tariff-rate quota for lean beef trimmings from Argentina by 80,000 metric tons, a day after the two countries finalized a broader bilateral trade agreement
• Cash cattle prices falling nearly 13 percent in the weeks following the announcement of the order before recovering
• Farm bankruptcies filed under Chapter 12 are up 46 percent compared to 2024, according to the American Farm Bureau Federation
• American soybean exports to China drop to near zero due to the administration’s tariff disputes with China
• The Iran war, which the U.S. entered in February 2026, added further pressure by disrupting fertilizer and diesel supplies, with urea prices jumping more than 40 percent in the weeks following the first strikes

Peel urged caution about overstating any single factor. “The major factor underlying it is just the state of supply combined with very, very strong consumer demand,” he said.

How Screwworm Made It to Texas

While the root causes of the screwworm’s northward march remain under study, scientists suspect a combination of human migration, illegal animal movement and weather patterns.

Facility Problems & Migration Considered Main Causes

Rollins, in a Thursday briefing, blamed the pest’s arrival in part on what she called “open border policies” and cartel-driven cattle movement in Mexico, saying there was “a lot to be desired in the Mexican response.”

“This fly typically moves great distances because humans move animals,” she said. “These flies do not fly to new areas on their own.”

Peel said overlapping factors allowed the pest to breach the barrier that had held it in Panama for decades:

• The sterile fly facility there had limited output capacity and had not kept pace with the cost of doing business.
• But the more significant factor was a change in cattle movement patterns.

“In Central America, because of more illegal movement of cattle in regions where they normally did not move, they sort of bypassed the areas where they were targeting the sterile flies,” Peel told Newsweek. Mexico compounded the problem, evolving over the past 15 to 20 years from a highly regional market to a fully national one, with feedlots in the north drawing livestock from the south.

“You combine all those factors, and you’ve got the opportunity for the screwworm fly to get past the barrier in Panama, make its way through Central America into Mexico, and then once it gets into Mexico, more national movement facilitated the rapid spread,” Peel said.

Climate Change, Budget Cuts Catch Blame, Too

Lee Haines, an associate research professor of biological sciences at the University of Notre Dame, said cold snaps that once suppressed stray populations in northern regions “are becoming rarer and less severe, thus removing a natural biological check on the flies’ migration north.”

Questions have also been raised about the federal budget and staffing cuts. APHIS, the USDA agency responsible for animal and plant health inspection, lost roughly a quarter of its workforce in early 2025, according to a USDA inspector general report, in reductions tied to the Department of Government Efficiency. International disease-prevention funding, including programs tied to screwworm monitoring, was cut in March 2025.

The USDA has disputed that the cuts hampered its response, pointing to $21 million to convert a facility in southern Mexico into a fly-breeding operation and $750 million allocated for a new fly factory in south Texas. Woodall credited APHIS for working to delay the pest’s arrival “for more than 18 months.”

What the Government Is Doing Now

• On Wednesday, the USDA deployed a unified incident command team with the Texas Animal Health Commission and established a 20-kilometer control area with quarantine and movement restrictions.
• Four million sterile flies were released that day alone, Rollins said.
• Beagles have been trained to sniff out the flies in companion animals crossing the border, where thousands of surveillance traps have also been deployed. Screwworm cases in Mexico have been found heavily in cats and dogs crossing into the United States.

Additionally, livestock ports on the border have been closed since May 2025.

Rollins acknowledged the closures have contributed to higher beef prices but said Trump agreed they were necessary. “The president agreed when we briefed him we had to keep our livestock producers as safe as possible,” she said. The ports will remain closed until further notice.

Calls For Action: Deploy SWASS & Sterile Flies

Texas Agriculture Commissioner Sid Miller issued a pointed statement Wednesday criticizing the USDA for what he called a slow and incomplete response.

“For months, the screwworm has advanced rapidly through Mexico in spite of the USDA’s existing gameplan,” Miller said. “Even though billions of sterile flies have been dispersed by USDA, the screwworm has still advanced over 1,100 miles from southern Mexico to Texas, and USDA has missed an important component.”

Miller called on President Trump to direct USDA to immediately deploy the Screwworm Adult Suppression System, or SWASS, a technology that uses attractants, bait, and targeted insecticides to suppress adult populations alongside sterile fly releases. “USDA already owns the playbook,” he said. “The only question is whether USDA will use it before this situation gets worse.”

Rollins said the sterile insect approach that eradicated the pest six decades ago remains the primary tool.

• A new dispersal center opened in South Texas in February.
• The $750 million factory in South Texas, which would produce up to 300 million sterile flies per week, is expected to be fully operational by fall 2026.
• The fly-breeding facility in southern Mexico is expected to begin operations next month.

Treatment Options & Moving Forward

Woodall said the FDA had also expanded treatment options, granting veterinarians access to commercially available products to help protect animal health. On surveillance, he said the most urgent need was “enhancing the ability to detect the pest while also monitoring wildlife populations in Texas and other border states so we know how and where it’s spreading.”

“If we all work together and follow animal treatment and the movement restriction guidance,” Rollins said, “there is no reason to believe that this incursion will result in any sort of establishment of the pest.”

Asked whether NCBA was confident the administration was balancing consumer prices against producer survival, Woodall said, “We’re hopeful that we can count on President Trump to continue to account for the needs of cattle producers as he works through the delicate balancing act of protecting the needs of all Americans,” he said.

2026 NEWSWEEK DIGITAL LLC.

This story was originally published June 5, 2026 at 2:00 AM.