Texas Faces New Cases of New World Screwworm

In Kerrville, Texas, officials confirmed two new cases of the New World screwworm in the state. This highlights the challenge of controlling a pest that could severely impact the cattle industry. The United States Department of Agriculture made this announcement on Monday.

The screwworm is a fly producing larvae that consume living flesh instead of dead tissue. Female flies lay eggs in open wounds of any warm-blooded animal, including livestock. Wildlife, pets, and sometimes even humans can become infested.

Recent cases involved a calf and a dog, several hundred miles apart, in La Salle and Andrews counties, according to the department. This brings the total number of confirmed cases to four. The screwworm was first detected last week in a three-week-old calf, with a second case found nearby in another young calf.

Dudley Hoskins, the department’s assistant secretary for marketing and regulation, stated, “While we address these cases requiring immediate attention and continue testing suspicious cases, we are also working to eradicate the pest completely.”

Before being eliminated in the United States in the 1960s, the fly was an annual warm-weather scourge for ranchers. Both the department and the U.S. livestock industry have been working diligently to prevent an infestation since the pest was detected in Mexico in late 2024, after being contained in southern Panama for decades.

The government combats the fly by breeding sterile male flies, which then mate with wild females. Wild females only mate once in their life. By mating with sterile flies, the females produce no offspring, gradually reducing outbreaks.

The department plans to increase the production of sterile flies in facilities outside the U.S. while constructing another facility in Texas.

Agriculture Secretary Brooke Rollins will receive updates on the infestation at the Livestock Insect Research Laboratory in Kerrville, Texas, on Monday afternoon.

This story was translated from English by an AP editor with assistance from a generative AI tool.