Flesh-Eating Fly Returns — Texas on Edge

A flesh-eating livestock parasite once wiped out in America is back in Texas, and how we handle it now will decide whether this becomes a border scare or a nationwide hit to ranchers’ pocketbooks.

Story Snapshot

New World screwworm has been confirmed in a Texas calf, reviving a pest that eats animals alive.
Experts say human risk is low, but the threat to cattle, wildlife, and ranch incomes is serious.
USDA and Texas officials are rolling out sterile-fly releases, checkpoints, and movement controls.
Border failures and weak oversight in Mexico and Central America helped this parasite march north.

What Exactly Is Back — And Why Ranchers Are Alarmed

The New World screwworm is not a normal fly. Its larvae burrow into the flesh of living animals and eat tissue from the inside out, often killing untreated livestock.^[20] Ranchers can see hundreds of maggots in one wound, usually in high-risk spots like the navel of newborn calves or branding and castration sites.^[20] Federal history records show screwworm was once one of the most destructive parasites in American agriculture until an eradication campaign finally pushed it out in the 1960s.^[21]

The United States Department of Agriculture (USDA) now confirms that this parasite has returned on American soil. Officials report a three-week-old calf in Zavala County, Texas, tested positive, with larvae found in the umbilical area.^[1] That is exactly the type of wound screwworm targets first. USDA calls the pest a “serious” threat to livestock, pets, wildlife, and, less often, people.^[1] For producers already fighting high feed, fuel, and land costs, the idea of animals being eaten alive feels like one more attack on their livelihood they did not cause and cannot easily control.

Although lab-confirmed cases are still limited, government maps and media updates show the numbers are climbing beyond that first calf. Texas outlets report multiple animal cases and an emergency declaration as infections spread through South Texas herds.^[11]^[16] USDA’s own screwworm response page now lists new detections in additional Texas counties, signaling that this is not a one-and-done incident.^[7]^[10] Ranchers understand how fast flies can spread in warm weather. With summer heat and heavy livestock traffic, the window to box this in is short.

How Did A Eradicated Pest Get Back Across Our Border?

The road back to Texas did not start last week. Since 2023, a major screwworm outbreak has marched north through Central America and into Mexico, hitting livestock, pets, wildlife and even people.^[3]^[13] By early 2026, health officials counted more than a thousand human cases and multiple deaths in the region, plus well over one hundred thousand animal infestations.^[13]^[1] In 2024, Mexican officials found screwworm in cattle at a checkpoint in Chiapas, confirming the parasite was moving steadily toward the U.S. border.^[4]

Washington did take some steps, but many producers feel they came late. USDA temporarily halted imports of cattle, horses, and bison from Mexico after detections in Veracruz, a Mexican state far north of earlier hot zones.^[12] Scientific modeling published in 2025 flagged Texas as one of the most suitable and highest-risk states if screwworm reached U.S. soil, due to its warm climate and huge livestock base.^[2] That warning is now reality. The fact that a pest we eradicated decades ago has strolled back in from the south looks, to many conservatives, like one more sign that weak border control and slow international enforcement always end up on the backs of American producers.

Veterinary experts stress that this is not just a Texas problem if it gets loose. Historical USDA economic estimates suggest screwworm could cost billions of dollars in cattle and wildlife losses in Texas alone if it became established.^[12]^[26] The parasite can infest any warm-blooded animal, including deer, sheep, goats, horses, and pets.^[18]^[20] That means ranchers, hunters, and rural families all carry the risk. For readers who remember the Florida Keys screwworm outbreak in 2016, which nearly wiped out endangered Key deer before aggressive sterile-fly releases, this Texas case feels uncomfortably familiar.^[5]

What The Government Is Doing Now — And What You Can Do

USDA’s Animal and Plant Health Inspection Service says it is moving fast to contain and wipe out the pest. The agency has activated its New World screwworm response playbook, which includes strict movement controls, checkpoints, and intense animal surveillance around the detection zone.^[1]^[2] Federal and Texas teams are visiting ranches, setting traps, checking livestock for suspicious wounds, and coordinating release sites for sterile flies that can break the breeding cycle.^[2] USDA is also building a new sterile-screwworm production plant in Edinburg, Texas, to supply the huge numbers of sterile flies needed to crush an outbreak.^[2]^[9]

Health agencies are walking a fine line between sounding the alarm and avoiding panic. The Centers for Disease Control and Prevention says there are no locally acquired human screwworm cases in the United States and that the risk to people remains low and limited to areas where the fly is circulating.^[3] USDA also stresses there is no food-safety risk; screwworm does not infest inspected meat, and the U.S. food supply remains safe.^[1]^[7]^[17] For most Americans, the threat is not eating beef. The real danger is fewer healthy cattle, tighter supplies, and more pressure on already high grocery bills.

🚨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

For conservative readers who own land, raise animals, or simply care about food security, there are clear action steps. Texas Animal Health Commission and Texas A&M experts urge ranchers to inspect livestock often, especially around the navel on young animals and any fresh wound.^[4]^[8]^[20] Look for foul-smelling, draining sores, visible maggots, or animals that lick or bite at a spot and seem restless.^[4]^[20] Any suspect animal should be isolated, not moved, and reported at once to a veterinarian or state animal health office, which is required to send larvae for official identification.^[4]^[8]

Families and pet owners near affected areas should keep wounds clean and covered and watch dogs and outdoor animals for strange wounds.^[3]^[8] Travelers to outbreak countries in Central America or Mexico should follow basic insect-bite precautions and cover any cuts, then seek medical help quickly if they see maggots in a wound after returning.^[3]^[13] None of this replaces the need for strong borders, honest reporting from foreign governments, and a serious focus on American agriculture. But it does give everyday citizens a way to help stop a dangerous parasite before it spreads and turns into the next expensive crisis dumped on working people.