New World screwworm threatens US livestock and prompts new sterile‑fly research

The New World screwworm, a flesh‑eating fly larva, was detected in the United States for the first time in decades in June. It infests cattle and other warm‑blooded animals, prompting the Dallas Federal Reserve to estimate potential economic damage in the billions for the Southwest and to warn of possible beef‑price increases.

Public‑health officials say the parasite does not pose a food‑safety risk because the larvae require living tissue, cannot survive in meat, and any infested animal would be caught by USDA meat‑inspection procedures. "It’s a threat to food, inasmuch as it’s a threat to food prices, but it’s not a threat from the perspective of food quality," said Maximillian Seunik of Screwworm Free Future, and Dr. Jonathan Cammack of Oklahoma State University added that meat would remain safe.

To curb the spread, the Foundation for Food & Agriculture Research, Agragene, and North Carolina State University have been awarded a $300,000 Rapid Outcomes from Agricultural Research grant to develop a new sterile‑male fly technique that preserves mating competitiveness better than traditional radiation methods. Dr. Maxwell Scott of NC State, who helped create the all‑male NovoFly strain, will lead the effort to suppress the screwworm population.

The combined response aims to protect livestock, stabilize beef prices, and prevent the parasite from establishing a larger presence in the United States.