Abbott Builds Response Team for Parasitic Flesh-Eating Flies

To prevent the creeping threat of an invasive parasitic fly, the New World screwworm (NWS), whose larvae burrow into open wounds and eat animals, including the occasional human, Gov. Greg Abbott has commissioned the Texas New World Screwworm Response Team. The screwworm, which can eat its way through entire herds, has wreaked havoc on the American cattle industry before, costing farmers and ranchers millions of dollars in an outbreak in the ‘60s.

The team, composed of the Texas Parks and Wildlife Department (TPWD) and the Texas Animal Health Commission (TAHC), is tasked with being “the first line of defense against the potential re-entry of this harmful pest into the United States.”

“[Texas] also leads the nation in cattle inventory, and its ranching and livestock industry is a cornerstone of both the Texas and United States economies. … Texas played a critical role in eradicating this pest from the United States in the 1960s and will do so again if the need arises. We stand ready to protect our land, livestock and wildlife,” wrote the governor in a letter to the executive directors of the TPWD and the TAHC.

According to the U.S. Department of Agriculture (USDA), screwworms were detected in Oaxaca, Mexico, roughly 700 miles from the United States border on June 18. Varying reports say an adventurous pest can travel up to 125 miles itself, but the spread is more common through the transportation of livestock, meaning those 700 miles are too close for comfort.

To mitigate the potential rapid spread of screwworms and protect the billion-dollar livestock industry, the USDA is constructing a sterile fly dispersal facility at Moore Air Base in Hidalgo County. There, scientists will breed sterile flies, up to 300 million per week, and release them for mating in Northern Mexico. The female screwworm is monogamous; they mate for life. When they attempt to procreate with the sterile male flies, the eggs are infertile, and the pest is eliminated over time.

The United States and Panama have maintained a barrier zone in Eastern Panama, where a permanent screwworm pupae sterilization facility keeps the species at bay. But since 2023, reports of species have slowly crept up Central America, now reaching the southern tip of Mexico. The state has been monitoring the situation and has taken the time to be well-prepared for an infestation.

“Texans can be assured that staff have been actively preparing and training for a possible New World screwworm response for over a year,” said Dr. Lewis R. “Bud” Dinges, TAHC executive director, in a press release. “While we hope we don’t have to deal with the pest on our soil, joint efforts to mitigate damage and protect all commodities from NWS are ongoing and will be bolstered by this well-rounded team.”

The fear comes as farmers, ranchers and non-vegans are just beginning to recover from a spike in bird flu in the United States that saw egg prices reach double digits in parts of the country. But Sam Parker, a spokesperson for HerdX, a herd management technology company, said farmers and ranchers are used to the industry's ebb and flow.

“The cattle industry, farmer and ranchers, don’t let fear rule their day-to-day,” Parker said over the phone, surrounded by farmers at a livestock showcase. “They’re resilient. They deal with a lot. If it was a threat, it’s not gonna show with this group of hard-working people.”

Our farmers have experienced their fair share of cataclysmic reckonings at Mother Nature's hands. In the worst-case scenario, a widespread NWS outbreak could be detrimental to farmers and the economy as a whole, Parker says.

“This could result in billions and billions of dollars of loss,” said Parker. “The cattle industry is like the stock market.”

But even if farmers and ranchers haven’t begun to sweat just yet, Parker says the immediate action of our state government is appreciated, especially as the risk in Mexico increases. The spokesperson says ranchers in Mexico are at a loss right now, as the country lacks an action plan to eradicate the pest. On May 11, the United States suspended all livestock imports from Mexico to reduce the spread and allow for easier livestock tracing.

“There’s [Mexican] feed yards doing everything they can to double labor, check for cuts,” said Parker. “This is why traceability is a big deal. It’s important that the U.S. and Texas step up and do what they did 60 years ago to mitigate this threat again.”