The U.S. Agricultural Research Service announced that a newly developed all-male screwworm strain called NovoFly™ has received full regulatory approval for use in pest eradication efforts in New Mexico and Texas.
NovoFly™, developed by researchers at the USDA's Knipling-Bushland U.S. Livestock Insects Research Laboratory in Kerrville, Texas, uses genetic engineering to kill female larvae during early rearing stages while allowing males to survive. This innovation allows production of twice as many male screwworms from the same amount of artificial diet and equipment.
The strain is designed for use in the Sterile Insect Technique (SIT), a pest control approach that releases sterilized male flies near infestation areas. The sterilized males mate with wild females, but the resulting eggs fail to hatch, collapsing the screwworm population without the need for pesticides.
The approach successfully eliminated the New World screwworm from the United States by 1966 and has been used to contain subsequent resurgences. The USDA highlighted SIT in January 2026 as part of a New World Screwworm Grand Challenge to counter recent U.S. incursions of the pest.
Because only sterile males are beneficial for SIT programs, NovoFly™'s all-male production doubles the effectiveness of releases. Previously, there was no efficient way to separate males from females before release. The screwworm pest causes significant harm to livestock by burrowing into wounds or mucus-lined openings.