Federal agricultural officials have confirmed the detection of New World screwworm larvae on a young calf in south Texas, raising concerns about potential risks to livestock in the region. The larvae, identified on a three-week-old calf near the U.S.-Mexico border, were found in the animal’s umbilical area in Zavala County, more than 60 miles north of the border.

The New World screwworm, scientifically known as Cochliomyia hominivorax, differs significantly from typical maggots that consume decaying organic material. Instead, these larvae infest and feed on living tissue, causing severe wounds that can endanger the health of affected animals. Tom Talbot, a veterinarian and member of the California Cattlemen’s Association, emphasized that unlike other maggots, screwworms actively attack living flesh, making them particularly dangerous to livestock.

The screwworm is native to South America and has historically been eradicated from the United States through extensive control programs, including sterilization and monitoring efforts. However, its recent reappearance near the border has prompted USDA officials to heighten surveillance and deploy containment strategies to prevent its spread further into U.S. cattle populations.

While the presence of the screwworm is concerning to ranchers and agricultural authorities, officials maintain that they are prepared to address the threat effectively. Measures such as quarantines, treatment of infected animals, and coordinated insect control efforts are expected to limit the larvae’s impact and reduce the likelihood of a broader outbreak.

The detection underscores the ongoing challenges posed by pests endemic to neighboring regions, particularly in border areas where cross-border movement of animals and goods may facilitate their introduction. Livestock producers in Texas and surrounding states have been advised to remain vigilant, regularly inspecting animals for signs of infestation and reporting any suspicious cases promptly to authorities.

The USDA continues to monitor the situation closely as efforts to contain and eradicate the screwworm in the affected area proceed. Officials have not indicated any confirmed cases beyond the initial detection, but remain cautious given the potential economic and animal health consequences should the infestation spread.