U.S. Initiates New Sterile‑Fly Program as Screwworm Returns to Texas
A Texas calf infected with the New World screwworm marks the first U.S. case since 1982, prompting the USDA to allocate $750 million for a new sterile‑fly facility to prevent a wider outbreak.
The U.S. Department of Agriculture confirmed that a calf in Texas tested positive for the New World screwworm, the first natural incursion in U.S. cattle since 1982, and reported a second case six miles away later that week. The discovery has revived concerns about the parasite, which can devastate livestock and, in rare cases, infect humans.
Officials said the response will mirror the program launched in the late 1950s, which relied on releasing large numbers of sterile male flies to interrupt reproduction. >"It is a tremendous strategy. It has worked and will continue to work moving forward," said Chad Cross, a parasitology professor at Texas Tech University. >"The new Texas case is a stark reminder of how quickly we need to act to ensure that it doesn’t spread further," he added.
Entomologists explained that the screwworm, a blowfly species, lays 200‑300 eggs in open wounds; the larvae feed on flesh, often killing cattle if not treated with larvicides and antibiotics. >"The larvae that emerge from the eggs consume the flesh of warm‑blooded animals," said Phillip Kaufman of Texas A&M University.
The USDA plans to spend $750 million on a Texas facility capable of producing about 300 million sterile flies each week, roughly three times current capacity and comparable to output in the 1960s. The plant is not expected to be operational until late 2027, leaving a window of heightened risk. USDA estimates suggest a widespread outbreak could cost Texas up to $1.8 billion annually in livestock losses and related expenses.
While the primary goal is to push the pest out of the United States and Central America, a group of bioethicists and scientists has debated whether eradication through genetic modification might be justified. Gregory Kaebnick of the Hastings Center noted that the discussion reflects a balance between preserving biodiversity and alleviating animal suffering, but emphasized that such technologies are not yet ready for deployment.