USDA announces new facility to strengthen fight against NWS
In the latest on the New World screwworm (NWS) front, the U.S. Department of Agriculture announced it has awarded a contract to Mortenson Construction to build a new sterile fly production facility at Moore Air Base in Edinburg, Texas.
The project will be completed in partnership with the U.S. Army Corps of Engineers (USACE), which will oversee the facility’s design, engineering and construction, and federal officials say the facility will play a key role in the nation’s strategy to prevent NWS from reaching the U.S.
“This first-of-its-kind facility on U.S. soil will ensure we are not reliant on other countries for sterile flies,” says U.S. Secretary of Agriculture Brooke Rollins in a March 9 news brief announcing the project. “The USACE is the best in the business, and their engineering expertise will help ensure we build a modern, resilient facility to protect American agriculture from invasive pests for decades to come.”
Northward spread
NWS is a parasitic fly whose larvae feed on the living tissue of warm-blooded animals.
When the fly lays eggs in an open wound or natural body opening, the larvae hatch and burrow or “screw” – hence its namesake – into flesh, causing severe injury and often death if left untreated.
The pest can infest livestock, wildlife, pets, occasionally birds and, in rare cases, it can also affect humans.
The U.S. originally eradicated the pest in 1966 through a successful large-scale sterile fly program, and since then, the U.S. Department of Agriculture (USDA) and its international partners have worked to keep the insect confined to South America.
However, NWS re-emerged in November 2024 with a detection in southern Mexico and has since moved northward with the most recent case reported in Nuevo León and Tamaulipas, Mexico – both situated near the Texas border – on March 3.
Although USDA’s efforts have kept the pest at bay, officials worry NWS will result in significant economic losses for producers should it cross the U.S. border.
Expanding efforts
The sterile insect technique (SIT) has been a cornerstone of NWS eradication efforts since its original outbreak in the 1960s and is still widely recognized as one of the most effective and environmentally responsible methods for controlling invasive insects.
In sterile fly production facilities, NWS flies are raised in a controlled environment and sterilized using irradiation. Sterile males are released into targeted areas where wild screwworm populations exist, and because female screwworm flies only mate once in their lifetime, mating with a sterile male results in eggs which do not hatch.
When combined with surveillance, movement controls and education efforts, SIT has proven successful in eliminating the pest in large geographic regions.
According to APHIS, the U.S. currently relies on sterile fly production at the Panama-U.S. Commission for the Eradication and Prevention of Screwworm facility in Panama, where roughly 100 million sterile flies are produced per week, then dispersed in and around affected areas in Mexico.
Recently, the USDA also invested $21 million to help Mexico renovate an existing fruit fly facility in Metapa, Mexico. Once complete, this facility is expected to produce an additional 60 to 100 million sterile flies per week, with production anticipated to begin in the summer of 2026.
The new facility in Texas is expected to add significant domestic production capacity to these international efforts as well.
“USDA and USACE will break ground on the new facility later this spring, after initial planning and development meetings with the new contractor,” USDA explains. “By November 2027, the production facility at Moore Air Base is expected to reach its initial goal of producing 100 million sterile flies per week. After that, construction will continue at the facility to increase production with a long-term goal of producing 300 million sterile flies per week.”
The agency adds, “The new facility at Moore Air Base will be the only U.S.-based sterile fly production facility and will work in tandem with facilities in Panama and Mexico to help eradicate the pest and protect American agriculture.”
A broader strategy
The new sterile fly production facility is part of USDA’s broader five-prong strategy announced during the summer of 2025 and designed to prevent NWS from spreading into the U.S.
The strategy focuses on stopping the pest’s northward spread across Mexico toward the U.S. Border, strengthening surveillance and protections along the border, improving emergency response readiness and expanding sterile insect production capacity.
In addition to increasing sterile fly production, the strategy includes enhancing surveillance programs, collaborating with Mexican officials, strengthening animal movement controls and expanding public outreach to livestock producers and rural communities.
USDA is also working with state animal health officials to update response plans and ensure veterinary laboratories are prepared to detect the pest quickly should a case occur in the U.S.
Hannah Bugas is the managing editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.
