Screwworm neutralizer: insect sterilization

The New World screwworm (Cochliomyia hominivorax) is back in the United States for the first time in decades, and it is every bit as unwelcome as its name suggests. This parasitic fly lays its eggs in the open wounds of warm-blooded animals, where they hatch into flesh-eating larvae that can devastate livestock, pets, wildlife and — thankfully rarely — humans. But in a nice twist of biological fate, the females of the species only mate once in their lifetime, making them perfect candidates for sterilization intervention. For SN, Fechi Inyama describes the mating disruption game called the Sterile Insect Technique.

🦟 The science of sterile swarms

The strategy makes sterile males by exposing immature flies to radiation, and then letting them loose via aerial drops or from specialized chambers on the ground. Wild females are effectively “tricked” into a reproductive dead end. Decades ago, this method successfully pushed the pest down to South America, but now it’s returned as far north as Texas and New Mexico. To stop the spread, the U.S. Department of Agriculture is ramping up production. The original sterilization technique makes sterile males and females, but a new technology awaiting regulatory approval, called NovoFly, makes only males, in essence doubling the fly supply.