Trump’s Climate Denial May Help a Livestock-Killing Pest Make a Comeback

To a throng of goats foraging in a remote expanse of Sanibel Island, Florida, the low whir of a plane flying overhead was perhaps the only warning of what was to come. As it passed, the specially modified plane dropped scores of parasitic New World screwworm flies through an elongated chute onto the herd.

Then the plane’s whir gave way to the swarm’s buzz. It was 1952, and the U.S. Department of Agriculture was conducting a series of field tests with male screwworm flies that had been sterilized with gamma radiation. The experiment’s aim was to get them to mate with their female counterparts, reduce the species’ ability to reproduce, and gradually shrink the population — and its screw-shaped larvae’s propensity to burrow into living mammals before swiftly killing their host — into oblivion.

It didn’t fully work, but the population did diminish. So the team of scientists tried again; this time in an even more remote location — Curaçao, an island in the Dutch Caribbean. That quickly proved to be successful, a welcome development after a decades-long battle by scientists, farmers, and government officials against the fly, which was costing the U.S. economy millions annually and endangering colossal numbers of livestock, wildlife, and even the occasional human. Within months, the screwworm population on Curaçao fell, and the tactic would be replicated at scale.