Key facts
- Scientists are conducting the first outdoor tests of genetically modified screwworm flies, NovoFly, in Panama.
- NovoFly is engineered to produce only male flies, which can be sterilized and released to reduce the wild population.
- The spread of screwworm infestations poses an estimated $1 billion threat to the Texas livestock industry.
- Current sterile fly production is insufficient to combat the widespread infestation across Mexico and into Texas.
- The U.S. EPA has proposed registering NovoFly, which would be the first genetically modified insect to receive full clearance.
Scientists are preparing to launch the first outdoor tests of genetically modified screwworm flies, known as NovoFly, at a U.S.-funded facility in Panama. This marks a significant step in developing a more effective method to combat the flesh-eating parasite that has spread through Central America and into the United States, posing a substantial threat to the livestock industry.
The New World screwworm fly lays eggs in open wounds of warm-blooded animals, and its larvae burrow through living flesh, potentially killing the host. For decades, the primary method of control has been the widespread dispersal of sterile screwworm flies, produced at a joint U.S.-Panamanian facility in Panama. However, recent infestations across Mexico and into Texas have overwhelmed the current production capacity, which stands at about 100 million sterile flies per week, far short of the estimated 500 million needed to establish a barrier.
NovoFly is engineered to produce only male offspring. These males can then be sterilized and released to mate with wild females, leading to unfertilized eggs and a progressive decline in the screwworm population. This approach aims to significantly increase the number of sterile males available for eradication efforts. Officials believe this could nearly double the number of sterile flies available for the fight against the pest.
Researchers will initially test NovoFly's survival and virility in mesh cages in Panama's climate before proceeding to larger field trials. These trials, expected to begin in nine to 12 weeks at a nearby ranch, will involve releasing marked insects and tracking their survival and mating competitiveness. Success is not guaranteed, as the flies' ability to fly far enough to find mates and their overall competitiveness against wild males remain key questions.
If successful, scaling up NovoFly production could occur at a new facility planned for Texas, rather than immediately at the Panama plant, to avoid disrupting current operations. The U.S. Environmental Protection Agency has proposed registering NovoFly, which would make it the first genetically modified insect to receive full EPA clearance. Mexico also supports the technology and may begin producing the flies by year-end.