Courtesy of USDA/APHIS
The battle against the new world screwworm isn’t being fought with insecticides or fences. Instead, USDA is deploying an unusual weapon, millions of sterile flies. It sounds like science fiction, but it’s a proven strategy called the sterile insect technique or SIT.
The idea is simple. Scientists raise screwworm flies in specialized facilities and expose them to gamma radiation, making them sterile without affecting their ability to fly, survive, or mate. Over time, the screwworm population shrinks and eventually disappears.
This isn’t an experimental approach. USDA says the technique helped eradicate new world screwworm from the United States in 1966 and was used successfully again to eliminate an outbreak in the Florida Keys in 2017. Today, USDA and Panama jointly operate the only sterile screwworm fly production facility in North America.
Located in Panama, the facility can produce more than 100 million pupae every week. Those flies are then released by aircraft or, when needed, from trucks and ground-based release stations in targeted areas. USDA is also working on future improvements, including a new technology known as NovoFly, a male-only strand designed to increase the efficiency of sterile fly releases.
The technology is still undergoing reviews and evaluations, but officials believe it could strengthen future eradication efforts. For livestock producers, the message is clear. Don’t worry about spotting the flies themselves.
Many fly species look alike, and some screwworm flies found during control efforts may actually be sterile flies released by USDA. Instead, producers are encouraged to regularly check animals for signs of infestation and report suspicious cases immediately.
Audio Reporting by Elizabeth Sanders for Southeast AgNet.