Last Modified: July 19, 2026
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  • NovoFlyTM is a novel strain of New World screwworm (NWS) that allows for production of male-only batches of NWS flies for use in USDA’s proven sterile insect technique (SIT) program 
  • The genetic process that kills females happens at a very early life stage, inside the production facility, not in the field. 
  • The NovoFlyTM carries a non-toxic, red fluorescent marker protein that allows for easy identification (for tracking and screening) compared to wild NWS flies.

Scientists at USDA’s Agricultural Research Service, in collaboration with North Carolina State University, developed NovoFlyTM. You can dive deeper into the decades of research that led to the development of NovoFlyTM on screwworm.gov.

  • Since SIT was first developed in the 1930s, scientists understood that male sterility was the primary driver of SIT success. Female NWS mate only once in their lives, but males mate multiple times. 
  • Current SIT production of NWS generates both males and females and there is no easy way to separate them. When sterile males and sterile females mate with each other after release, it reduces the number of sterile males available to mate with wild females, lowering program effectiveness. 
  • The NovoFly TM  strain solves this by producing only male flies, effectively doubling USDA’s supply of sterile NWS males for release. 

  • NovoFlyTM will be used as part of the existing SIT program, administered by USDA’s Animal and Plant Health Inspection Service (APHIS). 
  • All of the flies undergo irradiation, ensuring sterility and no reproduction, similar to the current SIT programs. 
  • However, this novel strain will also further enhance production efficiency and quality as male flies require lower levels of irradiation to achieve sterility. 

  • USDA APHIS determines where to release sterile NWS based on current detections.
  • NovoFlyTM must be approved by regulatory authorities prior to release, including by the U.S. Environmental Protection Agency (EPA), state-level regulators, and other countries’ regulators if used outside the United States.

NovoFlyTM must be approved by regulatory authorities prior to use, and will require some time to scale up production. 

  • EPA has evaluated the safety of NovoFlyTM and its use in USDA’s Sterile Insect Release program under its regulations and issued an emergency use exemption under Section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA, the primary regulation covering pesticides in the U.S.) for NovoFlyTM on June 8, 2026, subject to conditions set forth in the authorization letter. 
  • On June 12, EPA published its proposed decision to register NovoFlyTM under Section 3 of FIFRA with an additional opportunity for public comment, open until 11:59pm ET June 27, 2026.
  • EPA evaluates the potential for “harm to humans, wildlife, fish, and plants, including endangered species and other non-target organisms” prior to allowing the use of any pesticide, and concluded that when used according to the label, NovoFlyTM will not pose risks of concern to human health or the environment.
  • USDA will continuously monitor the efficacy of NovoFlyTM during production and in SIT operations.
  • For more information on EPA’s regulations, see their pesticide registration website. 

  • The EPA published the notice of receipt and request for comments in the Federal Register on March 27. 2026 and accepted public comments until April 27, 2026.
  • EPA published its proposed decision to register NovoFlyTM on June 12, with additional public comment period ending June 27, 2026.