The US Has a Plan to Combat Screwworm. It Involves a Lot More Flies
Key takeaways
- It took slightly longer, but the screwworm has arrived.
- A screwworm infection occurs when a female fly lays its eggs in open wounds or other body parts of warm-blooded animals.
- In the 1950s, researchers at the USDA made a breakthrough when they applied radiation to male screwworms and rendered them sterile.
Why this matters: a development in AI with implications for how people work, create, and decide.
Photograph: Dinar Bud/Getty Images Comment Loader Save Story Save this story Comment Loader Save Story Save this story. A flesh-eating parasitic fly that poses a major threat to livestock has returned to the United States after 60 years. This week, the US Department of Agriculture confirmed the presence of New World screwworm in a calf in southern Texas.
Eliminated in the US in 1966 and as far south as Panama by 2006, its recent reemergence in Mexico made it likely that the screwworm would eventually enter the country again, with modeling showing that it could arrive as soon as summer 2025. It took slightly longer, but the screwworm has arrived. And to head off an outbreak, officials are deploying a tried-and-true technique: releasing lots and lots of adult screwworm flies.
A screwworm infection occurs when a female fly lays its eggs in open wounds or other body parts of warm-blooded animals. When the eggs hatch, maggots emerge and feed on living tissue before turning into flies. As adults, screwworm flies do not bite or feed on flesh. Scientists in the 1930s and 1940s thought if they could prevent female flies from reproducing, they could break the cycle. At the time, New World screwworms killed hundreds of thousands of cattle annually, mostly in the American South and Southwest.