- September 16, 2026
Four southern California counties and 5 in southern Arizona have been added to Florida’s list of high-risk areas for New World screwworms after the parasitic fly was detected in the Mexican state of Sonora.
In June, the Department of Agriculture and Consumer Services imposed emergency rules to protect Florida’s cattle herds from the screwworm after it was found in Texas.
“We will stay ahead of this threat and continue to protect Florida’s livestock, pets, wildlife, and agricultural economy,” Agriculture Commissioner Wilton Simpson said in a released statement.
There have been no detected cases in Florida.
The protocols require all warm-blooded animals from infested zones to be certified by Florida two days before arrival in the state and inspected by a veterinarian within five days before arrival.
The restrictions also prohibit the import into Florida of shelter animals from an infested state.
The screwworm is a fly that lays its eggs in body openings and feeds on live animals, according to the U.S. Centers for Disease Control.
It was previously eradicated from the U.S. in 1966, except for a small outbreak in the Florida Keys in 2017. The flies have been moving slowly from Central America up through Mexico.
The screwworm does not affect the quality of the beef and is not a food safety issue.
