Flesh-Eating Fly Breaches Texas

A flesh‑eating livestock parasite once beaten by American science has slipped back across our border, and what happens next could decide the future of U.S. cattle country.

Story Snapshot

Federal officials have confirmed New World screwworm in a Texas calf near the Mexico border, the first U.S. animal case of this outbreak.
The parasite can eat living flesh of cattle, wildlife, pets, and in rare cases people, and once caused huge losses before its mid‑1900s eradication.
USDA and Texas leaders are rolling out surveillance, movement controls, and mass releases of sterile flies to wipe it out again.
Health agencies insist the risk to people and the food supply is low, but the economic threat to ranchers is very real.

What Exactly Is Back – And Why Ranchers Are Worried

The U.S. Department of Agriculture confirmed New World screwworm in a three‑week‑old calf in Zavala County, Texas, with larvae found in the umbilical area, a prime target for this parasite in newborn livestock.^[1] New World screwworm is a fly whose maggots feed on the living flesh of warm‑blooded animals, not dead tissue. They burrow into fresh wounds, causing deep, foul‑smelling lesions, severe pain, and often death if ranchers do not catch and treat cases quickly.^[1]^[20] This pest can hit cattle, wildlife, pets, and, rarely, people, making every untreated wound on the ranch a possible doorway.^[8]

Health and agriculture experts have warned for years that screwworm was pushing north through Central America and Mexico, with tens of thousands of animal cases and thousands of human cases in those countries.^[3]^[13] The border was always the weak link. Federal scientists note that Texas, with its huge cattle herds and warm climate, is one of the most suitable places in the country for screwworm to take hold if it gets past defenses.^[23] That is why even one confirmed calf matters: once these flies establish a breeding population, they can explode across pastures and wildlife in a single warm season.^[18]^[21]

How The Government Is Fighting Back – And What It Means On The Ground

USDA’s Animal and Plant Health Inspection Service says it is following its screwworm “Response Playbook,” which includes rapid containment in the area around the infected ranch, intense livestock surveillance, and strict controls on moving animals out of the zone.^[1] Texas officials say teams from USDA, the Texas Animal Health Commission, and Texas Parks and Wildlife are in the field, checking animals, educating landowners, and setting up checkpoints.^[2] Ranchers near the border have already dealt with import limits on Mexican cattle as Washington tried to slow the northward march of this pest.^[12]^[13]

The core weapon is the same conservative‑backed tool that won the original fight decades ago: the sterile insect technique. USDA leaders explain they are releasing millions of sterile screwworm flies on the ground and by air over South Texas, with more production capacity being built in a new facility in Edinburg.^[2]^[3] These sterile males mate with wild females, which then lay eggs that never hatch, driving the population down without constant chemical spraying. Researchers and USDA economists note that screwworm once cost ranchers billions in lost animals and treatment; getting ahead of it with sterile flies is cheaper than letting it spread.^[12]^[26]

Is This A Threat To People Or The Food Supply?

The Centers for Disease Control and Prevention reports no locally acquired human screwworm cases in the United States from this outbreak so far, and says the risk to people remains low and focused only where the flies are active.^[3] USDA’s unified screwworm site stresses that this is not a food‑safety issue and that screwworms do not infest meat, fruits, or vegetables.^[1]^[7] Texas health officials add that state and federal meat inspectors check animals for signs of screwworm before slaughter, giving families confidence that beef in the store is safe.^[17]

🚨New World Screwworm Update🚨
15 cases have been confirmed in total across the U.S, with 12 cases active in Texas. We have been preparing for this, and I am working with USDA @SecRollins to combat this pest, protect our livestock industry, and mitigate economic impacts. Read the…

— Rep. Monica De La Cruz (@RepMonicaDLC) June 22, 2026

At the same time, federal and state health agencies are warning travelers and border‑area residents to use common‑sense steps: keep all wounds clean and covered, use screens or nets against flies, and seek medical care fast if anyone sees maggots in a wound.^[3]^[13] A recent travel‑linked human screwworm case showed that, while people rarely get this infestation in the United States, modern global travel keeps the door open.^[14] Doctors and veterinarians have been told to report any suspected screwworm case right away so that public‑health and agriculture teams can move quickly.^[3]^[20]

What Conservative Ranch Families Can Do Now

Livestock experts in Texas say the most important front line is still the rancher walking his or her own fence line.^[8]^[18] They urge daily checks of cattle, sheep, goats, horses, and even working dogs for foul‑smelling wounds, restless behavior, or visible maggots, especially around navels of newborn calves and lambs, branding or castration sites, and ears.^[1]^[20] Any suspected screwworm case should be isolated, larvae removed and preserved for lab confirmation, and the animal treated under a veterinarian’s direction while all herd mates are inspected.^[8]^[20]

For many in farm country, this outbreak feels like one more blow after years of high feed costs, drought, and federal missteps on the border. But history shows that when American science partners with local landowners, screwworm can be beaten. USDA’s own archives call the first eradication one of agriculture’s greatest success stories, built on sterile flies and strong cooperation with ranchers.^[21]^[24] The sooner suspicious cases are reported and movement rules are followed, the better the chance that this parasite’s return to U.S. soil is brief—and that cattle country, not a flesh‑eating fly, decides the future of our food supply.