Flesh-Eating Maggots Hit Texas Cattle

A flesh‑eating maggot has finally crossed the border into Texas cattle country, and now ranchers are asking why Washington let it get this close.

Story Snapshot

First confirmed U.S. livestock case of flesh‑eating New World screwworm in 60 years alarms ranchers.
Texas leaders say federal officials moved too slowly while the parasite marched north through Mexico.
U.S. Department of Agriculture is racing to contain the threat with quarantines and sterile fly releases.
Billions of taxpayer dollars and decades of border strategy are now being stress‑tested in real time.

What This Flesh-Eating Maggot Is And Why It Threatens Cattle Country

The New World screwworm is a fly whose larvae are flesh‑eating maggots that burrow into open wounds of warm‑blooded animals, including cattle, wildlife, pets, and people.^[1] Once a female lays eggs in a cut or the navel of a newborn calf, the maggots hatch and literally eat the living tissue, which can kill an animal if not treated in time.^[1] This parasite was wiped out of U.S. livestock by the early 1980s, but it has been spreading again through Central America and Mexico in recent years.^[1] That slow northward march set up the risk we are now seeing spill over into South Texas.

Federal officials say a 3‑week‑old calf in Zavala County, Texas, is the first confirmed U.S. livestock case in about 60 years.^[4] Lab tests at the National Veterinary Services Laboratories in Iowa identified the larvae as New World screwworm, which triggered an official incident response.^[2]^[4] Agriculture Secretary Brooke Rollins has stressed that the current threat to human health is very low and that the parasite is not a food‑safety risk for the general beef supply.^[2] But she has also admitted this is a very serious danger to livestock, especially in calving season when newborns are most vulnerable.^[2]

How USDA Is Responding – And Why Critics Say It Was Too Late

After the Texas detection, the U.S. Department of Agriculture (USDA) and state officials set up about a 20‑kilometer infested zone around the ranch, with quarantines and tight rules on moving animals out of the area.^[2]^[4] Cattle and other livestock leaving that zone must be examined for up to 72 hours before they can move, which aims to catch any hidden larvae before they spread.^[4] USDA has also deployed personnel on the ground in South Texas, added surveillance traps, and launched door‑to‑door outreach to ranchers in the zone.^[2]^[4] These are classic “detect, control, and contain” tools from the federal foreign‑animal‑disease playbook.^[20]

Alongside boots on the ground, USDA is leaning on its long‑running “sterile insect technique” to beat back the screwworm.^[5] In this program, male flies are mass‑raised in specialized facilities, sterilized, then released in huge numbers over infected and at‑risk areas.^[5] Because female flies mate only once, if they mate with a sterile male, the eggs never hatch, driving the population down over time.^[1]^[5] USDA already produces and disperses about 100 million sterile flies each week along the southern border and into Mexico as a standing barrier.^[10] After the Texas case, officials say they are now ramping up those releases in the border region and directly over South Texas pastures.^[2]^[10]

Texas Leaders Blast ‘Too Little, Too Late’ While New Facilities Race To Catch Up

Texas Agriculture Commissioner Sid Miller argues this outbreak shows Washington waited too long and relied on a half‑measure while the parasite marched north.^[1] He has pointed out that as sterile flies were being dropped in southern Mexico, screwworm still advanced roughly 1,100 miles and finally crossed into Texas and New Mexico livestock.^[5] That criticism speaks to a broader pattern seen in livestock disease control, where delays often come from limited lab capacity, shortages of field staff, and the sheer difficulty of reaching remote ranches quickly.^[17] When every day counts, even a small lag can decide whether a pest stays contained at the border or becomes a home‑grown threat.

USDA counters that it has been preparing for this moment for years by building a stronger wall of sterile flies and new infrastructure.^[2]^[3] The agency is investing heavily to renovate and construct production and dispersal facilities in Mexico and the United States so it can flood the region with many more sterile males.^[3] A new domestic sterile fly production plant is being built at Moore Air Base in Edinburg, Texas, in partnership with the U.S. Army Corps of Engineers.^[11] That facility is designed to produce up to 300 million sterile flies per week, working with plants in Panama and Mexico to protect American cattle from future incursions.^[12]^[13] USDA has also completed a separate dispersal facility at Moore Air Force Base that can drop up to 100 million sterile flies per week along the Texas‑Mexico border.^[13]^[14]

What Ranch Families Should Watch For – And The Bigger Lesson On Government Readiness

For ranch families and rural communities, the immediate job is clear: spot cases early and follow movement rules so the parasite does not gain a foothold.^[5] Veterinarians and landowners are being told to inspect animals often, treat even small wounds, and contact their vet at once if they see suspicious maggots.^[5] USDA guidance says producers should work through local veterinarians, who then report to state animal health officials and federal area veterinarians in charge.^[5] When everyone follows that chain, federal and state teams can move faster with quarantines and treatments, instead of finding out after the pest has quietly spread across counties.

Four cases of New World screwworm have now been confirmed in the southern United States, with detections coming within days of each other. USDA Secretary Brooke Rollins says the agency was not caught off guard.

The US has committed $750 million to build a sterile fly breeding… pic.twitter.com/ocwCGsYPBi

— The HighWire (@HighWireTalk) June 19, 2026

At a deeper level, this outbreak exposes how fragile our animal‑health defenses can be when Washington waits until a crisis before fully funding border protection.^[1]^[19] The screwworm was beaten once, but experts warn that keeping it out now requires constant surveillance, strong cross‑border cooperation, and enough sterile‑fly capacity on U.S. soil to surge quickly when trouble appears.^[1]^[13] That means less money wasted on far‑off climate pet projects and more focused investment in the basic work of guarding our food supply, our ranch families, and the rural way of life that still feeds this country.