USDA Allocates $25M for Arizona Sterile Fly Facility to Combat New World Screwworm

USDA Expands Southwest Border Biosecurity Infrastructure

In a major biosecurity move along the U.S.–Mexico border, the United States Department of Agriculture (USDA) has committed $25 million to establish a state-of-the-art sterile fly dispersal facility in Douglas, Arizona.

Announced by Agriculture Secretary Brooke Rollins during an inspection of border livestock facilities, the funding expands the nation’s capacity to deploy the Sterile Insect Technique (SIT)—the primary biological control mechanism used to eradicate the flesh-eating New World screwworm (Cochliomyia hominivorax).

The new Douglas center complements the existing U.S. distribution hub in Edinburg, Texas, extending aerial sterile fly release coverage across 400 nautical miles from West Texas to San Diego, California, including the Sonora-Arizona border corridor.

Threat: What Is New World Screwworm?

The New World screwworm is an aggressive, obligate parasite of warm-blooded animals. Unlike typical blowflies whose larvae feed on dead tissue, female screwworms lay eggs in open wounds or natural body orifices of living animals.

• Production Risk: Left untreated, infestations cause severe tissue damage, secondary bacterial infections, and high mortality in cattle, horses, sheep, swine, wildlife, and domestic pets.

• How SIT Works: Female screwworms mate only once in their lifetime. When millions of laboratory-sterilized male flies are dispersed aerially over infested zones, wild females mate with sterile males, producing unviable eggs and causing wild populations to collapse.

Alignment with Border Port Reopenings

The $25 million investment aligns with the USDA’s phased strategy to reopen southern border ports of entry to Mexican feeder cattle.

Strategic Value for Ranches and the Beef Supply Chain

While the Douglas dispersal facility will take several months to become fully operational, its establishment addresses long-term concerns voiced by domestic producer organizations, including the Arizona Farm Bureau and national cattle associations.

By creating a continuous aerial sterile fly barrier along the entire southern border, the USDA aims to normalize cross-border livestock trade while safeguarding the domestic beef herd against invasive parasitic threats.