Screwworms have entered the US

The USDA announced this week that the New World screwworm—a flesh-eating fly that had been successfully kept out of the US for decades after wreaking havoc on cattle herds—has entered the country.

So far, it’s only one case. The agency’s Animal and Plant Health Inspection Service (APHIS) found a three-week-old calf in Texas with the larvae, marking the first case of screwworms in the state since 1966.

Screwworms are parasites that lay hundreds of eggs in a wound or orifice of a warm-blooded animal; those eggs then hatch and start eating the animal’s flesh. Beginning in the 1950s, the USDA was able to create a biological barrier by releasing millions of sterilized male flies from airplanes and pushing the screwworms south to Panama’s Darién Gap. But a year ago, cattle industry groups sounded the alarms about the risk of a return.

• The USDA claims that screwworms entering the US this year was inevitable and said it has invested in a new $750 million screwworm facility in South Texas. But the agency is also still navigating DOGE’s large workforce cuts, including 248 employees from the APHIS department in Texas.
• Texas Agriculture Commissioner Sid Miller accused the USDA on Wednesday of moving too slowly.

Big picture: Even a small infestation could jeopardize the already strained beef industry. The US cattle herd is at its lowest levels in 75 years.—MM