How Douglas could support Arizona’s fight against New World screwworm

USDA has announced an investment of up to $25 million for a sterile fly dispersal facility in Douglas, giving Arizona a new tool in the fight against New World screwworm.

Douglas has been part of the fight against New World screwworm before. The community was home to a sterile fly dispersal facility during the successful eradication campaign that ran from the early 1960s through the early 1980s. Newspaper accounts from the time, recently uncovered by the Douglas Public Library, show the scale of the operation. In 1964, officials expected to release about 8.5 million sterile flies each week from the Douglas center. By 1978, five USDA pilots were flying about 100 hours a week and dropping roughly 500 million sterile flies per week. Now, with an increase in screwworm cases in Mexico and the pest’s recent detection in the United States, the new facility would put Douglas back in position to support screwworm control efforts across the region.

University of Arizona Cooperative Extension experts worked with state and local partners and agricultural stakeholders to help make the case for the Arizona border facility. We talked with Amy Ganguli, a professor and Cooperative Extension Specialist who studies rangeland ecology and livestock systems, and Dari Duval, an Extension economist, about the effort, the proposed facility and what it could mean for Arizona.

This facility would represent a major investment in Arizona. How did the effort come together to bring it to Douglas, and what were the key factors that made it possible? 

Duval: That’s right, it’s a big win for Arizona agriculture. USDA announced it plans to invest up to $25 million in the facility, and it would support quality jobs in Douglas. During the 1960s New World screwworm eradication campaign, Douglas was home to a sterile fly dispersal facility, serving Arizona, New Mexico, West Texas, Southern California, and the Mexican states of Sonora, portions of Chihuahua, and Baja California. That facility closed following eradication in the U.S. Now, in response to the surge of New World screwworm cases in Mexico and its appearance in the U.S., USDA expressed interest in Douglas as a location to reestablish a sterile fly dispersal facility. 

We were part of an effort to coordinate state and local partners to respond to USDA with a proposal demonstrating the importance of Douglas as a location, providing potential siting options, and offering supporting information to inform their decision-making. This was an example of close collaboration between state and local partners and Extension, leveraging Extension’s on-the-ground networks to mobilize support in response to this need.

Why does Douglas make sense as a potential site for a new sterile fly dispersal facility?

Image

Duval: Douglas offers a number of strengths as a location for a dispersal facility. First, Douglas is an ideal location to cover portions of the U.S.-Mexico border not covered by the recently opened dispersal facility in Edinburg, Texas. The sterile flies are primarily dispersed by plane, and those dispersal flights have a range of a 400-mile radius. A Douglas facility would cover from West Texas to San Diego, covering key ports of entry that handle over 80% of live cattle imports from Mexico. Second, Douglas offers siting options at an existing airport, meaning that no additional transportation would be required to move flies from the facility to an airport. Third, there is strong community support locally and among industry stakeholders throughout the state, but also in neighboring states. Douglas’ historic contribution to the 1960s eradication campaign demonstrates the role it can play in addressing the current challenge, and there is an eagerness among the community and indstry stakeholders to resume that role.

Would this be a permanent facility, or is it a temporary reaction to the ongoing outbreak in Texas and New Mexico?

Ganguli: It’s not a short-term fix. The Douglas dispersal facility is expected to operate for the full length of the screwworm eradication efforts in both U.S. and Mexico. As part of the binational program, sterile flies are released year-round in Mexico to keep New World screwworm from moving north. The current infestation in parts of Texas and northern Mexico makes the need for sterile flies more visible, but long-term eradication work will continue. Douglas’s location on the border makes it a key asset that will support that ongoing effort. 

How are sterile flies produced, and how do they combat the spread of NWS?

Duval: New World screwworm pupae are exposed to radiation to render the males sterile, but they don’t become radioactive. Because female New World screwworm flies only mate once in their lives, a high enough concentration of sterile males released into an area will cause the local New World screwworm population to crash. There is currently a sterile fly production facility being constructed in Edinburg, Texas. Sterile fly production already takes place in Panama, as well as in a recently opened facility in Metapa, Mexico. Once it’s completed, flies produced at the Edinburg production facility could be transported to the Douglas facility for dispersal.

Are sterile fly releases safe?

Ganguli: Yes, the sterile insect technique has been demonstrated to be safe and effective at controlling screwworm populations. The technology dates back to the mid-20^th century, when it was used to successfully eradicate screwworm as far south as Panama. Alternative methods to control New World screwworm such as insecticides or larvicides are less practical because they would involve mass application of chemicals, which is not only technically challenging, but it could also introduce insecticide resistance and environmental concerns.

What is the timeline for construction and opening?

Duval: The details of the timeline have yet to be determined pending additional project scoping. 

If New World screwworm were detected in Arizona, how would this facility change the state’s response?

Ganguli: Arizona is fully cooperating with the federally led response to screwworm. This means following the USDA New World screwworm playbook, which lays out standard protocols and procedures for states to follow to confront this issue. In that sense, the facility likely won’t change the state’s response, but it will mean more resources and faster response if or when cases arise locally.

What does this facility mean for Arizona ranchers, veterinarians, pet owners and wildlife managers?

Duval: Once operational, this facility would help enable faster sterile fly dispersal in the southwest U.S. and northwest Mexico in response to reported cases. Fly dispersal is targeted in areas where cases are reported. In order to tackle this challenge, it’s critical that ranchers, wildlife managers, and the public in general report suspected cases when they find them. Producers and veterinarians are literally the “boots on the ground” and are our front-line in detecting and stamping out screwworm.

Ganguli: For reliable information, the best place to start is Screwworm.gov, which is USDA’s official site for updates, guidance, and national response efforts. In Arizona, people can also turn to the Department of Agriculture for reporting and state‑level information, Cooperative Extension for free sampling kits and education, and the Arizona Livestock Incident Response Team for on‑site support. Those are the trusted sources we encourage everyone to use.