US government to build $8.5M fly factory to mass produce millions of flesh-eating parasites in screwworm sterilization campaign

Fighting flies with flies.

The US government will be opening a fly factory in Texas to mass produce millions of infertile flies as part of a sterilization campaign aimed at eliminating a flesh-eating parasite with a penchant for beef.

The $8.5 million breeding facility, just 20 miles from the US-Mexico border, will focus on the New World screwworm flies wreaking havoc in Mexico after an outbreak last year, Agriculture Secretary Brooke Rollins announced Wednesday.

The factory will propagate millions of sterile male screwworm flies to be released into the wild. The male flies will seek out fertile females and help prevent them from laying eggs, which they frequently deposit in cows’ open wounds.

When left to fester, flesh-eating larvae burst from the eggs and can decimate entire herds of cows.

While the flesh-eating parasites are treatable, they can spread to virtually any mammal, including household pets and, in some cases, humans.

The Texas facility will mark the second of its kind on the Western Hemisphere. Up until now, Panama held the sole factory that helped prevent the screwworm flies from migrating north until last year.

Two more fly breeding facilities are on the horizon, too.

The Department of Agriculture also plans to spend $21 million to convert a separate facility that breeds fruit flies near Mexico’s southern border with Guatemala into a screwworm fly factory that won’t be complete until the end of 2026.

The USDA added that it is considering constructing a companion breeding center near the Texas one that would produce up to 300 million flies a week.

The US tackled a prior screwworm fly issue during the 20th century through the same method and eventually eradicated the gnarly pests from the country in the 1960s.

Before that, screwworms were a persistent issue for cattle farmers in the Southeast.

“The United States has defeated [the New World screwworm] before, and we will do it again,” Rollins assured at a news conference Wednesday.

Mexican Agriculture Secretary Julio Berdegué celebrated the multi-nation collaboration in a post on X and called Rollins’ plan “a positive step in different aspects” that “will strengthen the joint Mexico-US work.”

“We trust the enthusiasm for cooperation that Secretary Rollins mentioned, and based on objective results and the reports from the USDA mission visiting us this week, we will be able to restart exports of our cattle as soon as possible,” he wrote.

The USDA warned that the flies have been detected just 700 miles away from the US border. Some agriculture and cattle industry officials in the US worry that the swarms could be at the border by the end of the summer — right when calving season starts.

With Post wires