The US Department of Agriculture said on 29 July it will invest $25 million in a new sterile fly dispersal facility in Arizona, strengthening the long-running campaign against New World screwworm.

The sterile insect technique works by releasing males that cannot father offspring, so wild females mate without producing larvae and the population collapses. It is one of the few pest control methods that can eradicate rather than merely suppress, and it depends entirely on having plants close enough to release flies where they are needed.

The proposed Douglas facility would complement existing investment in Texas, Mexico and Panama and shorten the department's response time along the south-western border. Construction could take as little as several months depending on the site chosen, and the department is working with the Arizona Department of Agriculture on the location.

The announcement came as Agriculture Secretary Brooke L. Rollins visited livestock inspection facilities at the Douglas port of entry, which is due to reopen to cattle trade on 24 August after a year's closure.

"The Douglas Port of Entry will reopen only because USDA has implemented one of the most rigorous livestock inspection protocols in history," Rollins said, adding that the investment was part of a strategy "to push this pest back into Mexico and ultimately eradicate it from North America."

Officials from the Animal and Plant Health Inspection Service said trapping near Douglas over the past year submitted nearly 1,000 flies, none of which were identified as screwworm. Every animal entering through the port will face multiple veterinary inspections, including by USDA veterinarians before it crosses; any animal failing the import criteria is refused, and a detection would halt imports immediately.

Douglas was chosen first because Sonora maintains one of Mexico's strongest animal health systems. The department says the Santa Teresa and Columbus ports in New Mexico will be considered after Douglas has reopened successfully.

Source: USDA