The USDA committed $25 million for a new sterile fly dispersal facility in Arizona to help contain the New World screwworm on July 29. The parasitic pest, which kills livestock by burrowing into living tissue, has recently been detected in Texas.
The screwworm’s spread from Mexico into Texas has raised alarm across the U.S. cattle industry, prompting the closure of southern cattle ports and the development of a joint action plan with Mexico, the USDA said.
The Arizona facility will produce and release sterile male flies to disrupt screwworm breeding populations using the sterile insect technique, a proven biological control method the USDA has employed against the pest since the 1950s. The technique works by flooding an area with sterile males that mate with wild females, producing no offspring.
The $25 million investment supplements existing sterile insect technique capabilities and represents the key infrastructure component of the long-term containment strategy. Without adequate sterile fly production capacity, the USDA cannot maintain the biological barrier that has kept the screwworm out of U.S. cattle herds for decades.
The USDA announced a phased reopening of southern cattle ports beginning Aug. 24, contingent on Mexico’s adherence to the joint action plan. The port closures have disrupted cross-border cattle trade and affected ranchers on both sides of the border.
The New World screwworm was eradicated from the United States in the 1960s through the sterile insect technique and has been held at bay through ongoing suppression programs in Central America. Its reappearance in Texas marks the first domestic detection in decades.
For the U.S. cattle industry, the screwworm poses a serious economic threat. An unchecked infestation could devastate livestock herds and trigger trade restrictions from international partners.