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Arizona has secured a critical component in the fight against New World Screwworm.

The federal government is contributing $25 million to reopen a sterile fly distribution center in Douglas.

United States Department of Agriculture (USDA) Secretary Brooke Rollins announced the investment on July 29 during a visit to Douglas, where she also discussed plans to reopen the border with Arizona Farm Bureau members and others.

“The sterile insect technique is the only proven method to eradicate New World Screwworm,” Rollins noted shortly after on social media, “and we will continue expanding this critical tool to protect America’s livestock and food supply.”

The Douglas border port is first in line to reopen on Aug. 24, presuming Mexico meets goals in a previously approved plan to monitor and rein in the pest.

Ports in Santa Teresa and Columbus, N.M., would reopen at least 30 days after Douglas.

Nearly 70% of cattle imported to the U.S. travels through these three ports.

USDA has beefed up staff, surveillance

No cattle, horses or bison have been admitted from Mexico for more than a year in hopes of slowing the spread of this destructive pest.

But Rollins said the USDA now has the surveillance, staff and protocols in place to resume trade while keeping American cattle safe.

More than 8,000 surveillance traps have been deployed on the southern border, with more than 1,000 drone flights and 130 trail cameras monitoring livestock and wildlife for signs of infestation.

The Department of Homeland Security also has trained more than 24,000 frontline personnel to identify New World Screwworm at the border.

Its larvae thrive on living flesh, causing painful wounds in livestock, wildlife and pets that are treatable if caught early.

Mexico has confirmed more than 35,000 cases since 2024, with more than 1,800 active cases now.

Of the 42 cases confirmed in Texas and New Mexico since June, only nine remain active, and all affected animals have fully recovered.

Cattle will undergo multiple inspections

Rollins said the Douglas port is best positioned to reopen first, in part because the geography and climate are less favorable to screwworm survival than areas farther west.

The closest screwworm case is more than 250 miles away, and Sonora — the Mexican state it borders — is one of few remaining without a confirmed screwworm presence.

Cattle must be inspected by an accredited Mexican veterinarian before they arrive at the port.

They also must be outfitted with an electronic ear tag that can be quickly scanned for required origin and inspection information.

Once at the border, cattle will undergo a four-step inspection and treatment process, including a pass through an insecticide dip, before entering the U.S.

“The reopening will remain strategic and responsive,” Rollins posted on social media after the announcement. “And protecting American livestock will always come first.”

Sterile fly facility is crucial

The Douglas sterile fly facility won’t be online in time for the Aug. 24 port reopening, but the facility is crucial to lower infestation risks long-term.

Arizona Farm Bureau has advocated strongly to reopen the airport facility that closed decades ago, after the screwworm was eradicated in the U.S.

Distributing sterile flies in infested zones is crucial because female screwworms only mate once in their lifetime. If they mate with a sterile fly, their eggs won’t develop, crashing the population over time.

The Douglas facility would not produce these flies, but it is ideally located to distribute them 400 nautical miles — from west Texas to San Diego, including all of Arizona and Sonora.

Its coverage area perfectly dovetails areas served by the recently opened distribution facility in Edinburg, Texas, providing continuous coverage along the nation’s southern border.


Joanna Allhands writes about water, land use and other issues important to the Arizona Farm Bureau. Reach her at joannaallhands@azfb.org.