For decades, Americans believed the nightmare was over.
The flesh-eating parasite that once terrorized livestock across the southern United States had been driven out, pushed far beyond America’s borders through one of the largest insect-control campaigns in history.
Now, after nearly 60 years, it has returned.
And officials are scrambling to stop it before it spreads.
The alarming discovery was confirmed this week when federal authorities identified the first U.S. case of New World Screwworm infestation since 1966.
The victim was a three-week-old calf found in La Pryor, Texas, a small community located just 30 miles from the Mexican border.
Inside the calf’s umbilical wound, investigators discovered the parasite’s larvae — a finding that immediately triggered emergency containment measures.
The New World Screwworm is not an ordinary insect.
Experts often describe it as one of the most destructive parasites in the animal kingdom.
Unlike common flies that feed on dead tissue, female screwworm flies seek out living animals. They deposit eggs inside open wounds, eyes, noses, mouths, ears, and other vulnerable areas.
When the eggs hatch, hundreds of larvae begin consuming living flesh.
The infestation can rapidly grow, creating massive wounds and often killing the host if treatment is not provided quickly.
The gruesome feeding behavior has earned the pest a chilling nickname among ranchers: the “flying piranha.”
Now Texas officials are racing against time.
The U.S. Department of Agriculture has established a 20-kilometer control zone around the infected area while implementing quarantines, livestock movement restrictions, and intensified surveillance operations.
But the most unusual weapon in the government’s arsenal is not a pesticide.
It’s millions of flies.
Specifically, sterile flies.
Scientists have spent decades using a strategy known as the Sterile Insect Technique.
The process involves breeding huge numbers of screwworm flies in specialized facilities. The insects are then exposed to radiation, rendering them sterile before being released into the wild.
Because female screwworms mate only once during their lifetime, encounters with sterile males prevent future generations from being born.
The strategy helped eradicate screwworms from the United States decades ago.
But this time there is a problem.
Officials estimate they need roughly 600 million sterile flies every week to effectively suppress the growing population.
Current facilities in North America can only produce about 100 million per week.
That gap has sparked growing concern among ranchers and agricultural experts.
Agriculture Secretary Brooke Rollins attempted to reassure the public, revealing that millions of sterile flies have already been released since the infected calf was discovered.
“We have no reason to believe this will become established,” she said.
Not everyone is convinced.
Many Texas cattle producers argue that the response has been too slow.
Some point to the dramatic resurgence of screwworms across Central America in recent years.
After being largely contained south of Panama’s Darién Gap for decades, the parasite began marching north again.
By 2024, infestations had been confirmed in Mexico.
Now they have reached American soil.
Adding to the response effort is an unusual team of four-legged specialists.
Known as the “Beagle Brigade,” specially trained dogs are being deployed at border crossings and inspection points.
The dogs are capable of detecting livestock, animal products, and signs of infestation that humans might miss.
Their mission is simple: stop infected animals from carrying the parasite deeper into the United States.
While the threat to humans remains relatively low, health officials are warning people not to ignore suspicious wounds.
The parasite can infect people under the right conditions, and authorities have already recorded thousands of human cases across affected regions during the current outbreak.
The economic threat may be even greater.
Texas is home to one of the largest cattle industries in the world.
A widespread screwworm outbreak could devastate ranches, disrupt meat production, increase costs for farmers, and eventually drive up beef prices for consumers nationwide.
Climate conditions may also be working in the parasite’s favor.
Experts say warming temperatures could allow screwworms to survive in areas previously considered too cool for long-term establishment.
For now, officials are urging ranchers to carefully inspect livestock, treat wounds immediately, and report any suspicious infestations.
The battle that America thought it won decades ago may be starting all over again.
And this time, millions of sterile flies, highly trained dogs, and emergency containment zones stand between Texas and a parasite that literally eats its victims alive.
