The first center for dispersing sterile screwworm flies from U.S. soil in decades opened Monday in Texas, part of a larger effort aimed at keeping the New World screwworm parasite from crossing the Mexican border and damaging the American cattle industry.
U.S. Agriculture Secretary Brooke Rollins and Texas Gov. Greg Abbott unveiled the new facility at a former Air Force base near Edinburg. Officials said the Texas site will allow the U.S. to disperse millions of sterile male screwworm flies bred in Mexico or Panama on both sides of the border.
Rollins described the move as a coordinated response, calling it “a real testament to the all hands on deck — federal state and local — the fact that we do not have the pest in our country yet,” according to the Associated Press report. The USDA said the sterile males would mate with wild females, which mate only once during their adult lives, and that the females’ eggs—laid in open wounds or on mucous membranes—would then not hatch into the flesh-eating maggots that can infest livestock, wild mammals, household pets and even humans.
USDA also said it is expanding domestic breeding capacity. The department is building a new $750 million factory near the Texas dispersal center for breeding sterile flies, and Rollins said construction on that fly factory is not expected to finish until the end of 2027.
In parallel, the USDA said it will convert a fruit fly breeding facility in far southern Mexico into a screwworm breeding facility starting this summer. The plan is designed to increase the upstream supply of sterile males, while the Texas facility supports the near-term dispersal effort from the U.S. side of the border.
Officials framed the Texas center as a gap-filling step. The USDA opened a facility in Tampico, central Mexico, in November for dispersing Panama-bred flies, but the report said that site is about 330 miles (530 kilometers) south of the U.S.-Mexico border.
The new Texas dispersal effort also comes as the U.S. has restricted imports of cattle, bison and horses. Mexico’s cattle industry has been hit hard by screwworm fly larvae infestations, and the U.S. has closed the border since July to imports of those animals, according to the AP report.
The Associated Press report said the U.S. previously eliminated screwworm from American soil through a similar sterile-male fly program by the early 1970s, aside from a limited, short-lived outbreak in the Florida Keys in 2017 and a recent case when officials blocked a horse being imported from Argentina into Florida until it was fully treated. It said the U.S. shut down its fly factories after eradicating the pest domestically, and that sterile males have been bred in the Western Hemisphere only at a single facility in Panama that produces about 117 million a week—while the Texas fly factory is expected to be designed to produce 300 million a week.
Last month, the USDA also announced it would offer up to $100 million in grants for projects intended to improve fly breeding, create new fly traps and lures, and produce treatments for screwworm infestations.