Sterilizing screworms

A new sterile-fly production plant opened in Metapa de Domínguez, Chiapas, Mexico, on June 27, 2026. The $50 million facility will produce up to 100 million sterile flies per week, doubling the current production capacity from the long-running facility in Panama. The flies are released over infested areas, where sterile males mate with wild females. Because female screwworm flies mate only once, they lay infertile eggs, causing the population to collapse over time.

USDA says the sterile insect technique is the cornerstone of eradication. Sterile male flies do not produce larvae and cannot harm people or animals. They're released only to interrupt reproduction of the wild screwworm population.

Additional U.S. efforts include:

A sterile-fly dispersal center operating in Edinburg, Texas.

Construction of a much larger Texas production facility expected to eventually produce 300 million sterile flies per week.

Continued aerial and ground releases of millions of sterile flies in Texas following the detection of screwworm in June.

The basic concept is straightforward:

Millions of male screwworm flies are raised in specialized facilities.

They are sterilized using radiation.

Aircraft release them over affected regions.

Wild females mate with the sterile males.