Flesh‑Eating Maggots Invade Texas Cattle

A flesh‑eating maggot has finally crossed our southern border into Texas cattle, and now ranchers are asking why Washington waited so long to act.

Story Snapshot

A deadly flesh‑eating screwworm has re‑entered U.S. livestock for the first time in about 60 years.
Texas leaders say federal officials leaned too hard on slow, long‑range plans instead of urgent front‑line action.
USDA now scrambles with quarantines, sterile‑fly drops, and new Texas facilities after the pest marched north through Mexico.
The outbreak exposes wider worries about border security, food security, and how fast Washington can react when rural America is on the line.

Flesh‑Eating Maggots Reach Texas After Marching Up From Mexico

The New World screwworm is not a normal fly. Its larvae eat the living flesh of warm‑blooded animals, especially newborn calves and animals with open wounds. Once common in the southern United States, it was wiped out here by the early 1980s using a “sterile insect” campaign that pushed the parasite back into Central and South America.^[1] For decades, that success let America build a strong cattle industry without this constant threat hanging over every rancher’s head.^[16]

That firewall started to crack in recent years as screwworm spread north again through Central America and into northern Mexico.^[1] Federal health alerts warned that the pest was moving closer to the U.S. border months before the first Texas case, yet officials still relied heavily on releases of sterile flies far to the south.^[7] The first confirmed U.S. livestock case in about 60 years came in a three‑week‑old calf in Zavala County, South Texas, and more cases in Texas and even New Mexico soon followed.^[4]^[5]

What USDA Did – And Why Critics Say It Was Not Enough

After the Texas calf tested positive, the U.S. Department of Agriculture (USDA) set up an “infested zone” about 12 miles across, with quarantines and animal‑movement checks.^[2]^[4] USDA teams and Texas officials began trapping flies, inspecting herds, and tightening controls on livestock leaving the area. The agency also ramped up use of its main weapon: the sterile insect technique, where millions of sterile male flies are dropped by air so that wild females lay eggs that never hatch.^[5]^[10]

USDA points out that it has been releasing roughly 100 million sterile screwworm flies each week in Mexico as a long‑term shield for the United States.^[10] It has also invested in new and upgraded facilities in Mexico and Texas to produce and disperse these sterile flies, and is now building a major production plant at Moore Air Base in Edinburg, Texas.^[11]^[12]^[13] When running, that plant is expected to turn out up to 300 million sterile flies per week to protect the border states and support operations further south.^[12]^[13]

Texas Pushback: ‘Too Slow, Too Far Away From the Front Lines’

Texas Agriculture Commissioner Sid Miller has been blunt: Washington moved too slowly and leaned on a partial plan while the threat marched north. He argues federal officials trusted a sterile‑fly line deep in Mexico long after it was clear the barrier was slipping and the parasite was moving toward the border anyway.^[1]^[6] By the time the Texas case surfaced, screwworm had traveled hundreds of miles north through Mexico, and Miller says ranchers are now paying the price for that delay.

Miller and many Texas producers also question whether years of focusing on foreign facilities and slow‑moving international agreements left the United States without enough emergency capacity on its own soil. Congress only moved recently to back a domestic sterile‑fly plant in Texas, even though experts had called for that investment earlier.^[6]^[12] That timing feeds a familiar frustration in farm country: coastal agencies talk about “preparedness,” but when trouble hits the border, real tools show up late and in too few numbers.

Is the Food Supply Safe – And What Comes Next for Ranchers?

Federal officials stress that this outbreak is not a food‑safety crisis. USDA says the New World screwworm does not threaten the safety of the U.S. food supply, and the current risk to people is very low.^[2]^[3] In past cases, human infections have been rare travel‑related events that doctors can treat when caught early.^[1] The real danger is to livestock and wildlife, where untreated infestations can cause intense suffering, heavy weight loss, and even death, especially in young animals.^[1]^[5]

The threat of New World Screwworm is real in NM – that’s why, in addition to calling on the USDA to expedite the completion of the sterile fly facility in Texas at any cost necessary, I’m proud to announce another solution: new legislation to combat the spread of this pest, my…

— Rep. Gabe Vasquez (@RepGabeVasquez) June 19, 2026

For cattlemen, the bigger worry is whether this parasite can take hold and spread across grazing country. Research on past animal‑disease outbreaks shows that even modest delays in response can drive up costs, lengthen quarantines, and rattle meat demand.^[17]^[18] Ranchers are being urged to check animals daily, treat every wound, follow movement rules, and report anything suspicious fast so teams can move in.^[5] The next months will test whether today’s federal and state systems can match the speed and grit that wiped screwworm out the last time.^[16]^[20]