By Tom Polansek
CHICAGO, July 29 (Reuters) – The U.S. Department of Agriculture will spend $25 million on a facility in Arizona to disperse sterile flies used to combat the flesh-eating livestock pest New World screwworm, the agency said on Wednesday.
The facility will expand Washington’s efforts to control the spread of screwworms as the USDA plans to lift a ban on imports of Mexican cattle that it imposed more than a year ago in an attempt to keep the pest out of the U.S.
The ban on Mexican cattle helped push U.S. beef prices to record highs, hurting consumers and putting pressure on President Donald Trump’s administration to lower costs. However, the decision to resume imports drew criticism from some U.S. cattle producers, who said it would increase the risk for screwworm infestations.
The most effective tool against screwworm is sterile flies, according to the USDA. Arizona Governor Katie Hobbs sent a letter to the agency on Wednesday that proposed a dispersal facility for them in Douglas, Arizona, according to a post on X.
The USDA said on Friday that it planned to resume importing Mexican cattle at a port of entry in Douglas on August 24, and then eventually open two additional ports of entry in New Mexico.
“The continued threat of New World screwworm, prolonged disruptions to livestock trade, and additional costs for producers could keep beef prices elevated and further strain household grocery budgets,” Hobbs said.
Screwworms are parasitic flies whose females lay eggs in open wounds and mucous membranes on any warm-blooded animal. Once the eggs hatch, hundreds of screwworm larvae use their sharp mouths to burrow through living flesh, eventually killing their host if left untreated.
The pest has moved north through Central America and was detected in June on Texas farms and in New Mexico.
The USDA has said it needs many more sterile flies to push the pest back to the geographic boundary of the Darien Gap, the stretch of rainforest between Panama and Colombia. The agency is constructing a $750 million production plant for sterile flies in Texas.
(Reporting by Tom Polansek in Chicago; Additional reporting by Leah Douglas in Washington; Editing by Bill Berkrot)
By Tom Polansek | Reuters | © Copyright Thomson Reuters 2026.
