The United States is embarking on an ambitious, multi-million dollar project in southern Texas to combat the threat of flesh-eating maggots, with plans to construct a $750m factory dedicated to breeding billions of sterile flies. This significant investment aims to prevent the New World screwworm from crossing the border from Mexico and devastating the American cattle industry.
Brooke Rollins, Secretary of the US Department of Agriculture, announced on Friday that the new facility, located on Moore Air Base outside Edinburg, Texas – approximately 20 miles from the border – is expected to begin producing and releasing sterile male screwworm flies into the wild within a year. Alongside this, the US Department of Agriculture plans to deploy $100m in advanced technology, including fly traps and lures, and enhance border security with "tick riders" on horseback and specially trained dogs to detect the parasite.
The US border will remain closed to imports of cattle, horses, and bison from Mexico until the pest is successfully pushed back south towards Panama. This follows three border closures in the past eight months, the most recent in July, after an infestation was reported about 370 miles from the Texas border.
American officials are gravely concerned that if the screwworm reaches Texas, its flesh-eating maggots could inflict billions of dollars in economic losses and further inflate already record-high retail beef prices. The parasite also poses a threat to wildlife, household pets, and, on occasion, humans.
"Farm security is national security," Ms Rollins stated during a news conference at the Texas State Capitol in Austin, alongside Texas Governor Greg Abbott. "All Americans should be concerned. But it’s certainly Texas and our border and livestock producing states that are on the front lines of this every day."
The screwworm was a persistent problem for the American cattle industry for decades until the US largely eradicated it in the 1970s by breeding and releasing sterile male flies. Fly factories on US soil were subsequently shut down.
The Mexican cattle industry has been severely impacted by both infestations and the resulting US import bans. Mexico’s Agriculture ministry confirmed on Friday that Secretary Julio Berdegué Sacristán and Ms Rollins signed a screwworm control action plan. This includes monitoring with fly-attracting traps and mandating that livestock can only be moved within Mexico through government-certified corrals. On the X social media platform, Mr Berdegué expressed, "We will continue with conversations that lead to actions that will permit the reopening of livestock exports."
The new Texas factory will be the first on US soil in decades, marking a substantial increase in the US Department of Agriculture's investment in breeding and releasing sterile New World screwworm flies. The strategy relies on releasing sterile males in such large numbers that wild females are compelled to mate with them, resulting in sterile eggs that do not hatch. This eventually causes the wild fly population to dwindle, as females mate only once in their weekslong lives.
In June, Ms Rollins announced a separate plan to convert an existing fruit fly breeding factory for screwworms, along with a site near Edinburg for gathering flies imported from Panama and releasing them from small aircraft. Those projects are estimated to cost $29.5m. While the Panama factory can breed up to 117 million flies a week, and a new Mexican factory is expected to produce up to 100 million more weekly, the new Texas facility is projected to produce up to 300 million flies per week. Ms Rollins noted that the administration of President Donald Trump had sought to end the US’s reliance on foreign fly breeding.
"It’s a tactical move that ensures we are prepared and not just reactive, which is today what we have really been working through," Ms Rollins concluded.
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Hanna reported from Topeka, Kansas. Associated Press writer Fabiola Sánchez in Mexico City contributed reporting.
