Interesting article, might be behind paywall,
Excerpt:
…,
The United States has, for 70 years, been fighting a continuous aerial war against the New World screwworm, a parasite that eats animals alive: cow, pig, deer, dog, even human. (Its scientific name, C. hominivorax, translates to “man-eater.”) Larvae of the parasitic fly chew through flesh, transforming small nicks into big, gruesome wounds. But in the 1950s, the U.S. Department of Agriculture laid the groundwork for a continent-wide assault. Workers raised screwworms in factories, blasted them with radiation until they were sterile, and dropped the sterile adult screwworms by the millions—even hundreds of millions—weekly over the U.S., then farther south in Mexico, and eventually in the rest of North America.
The sterile flies proceeded to, well, screw the continent’s wild populations into oblivion, and in 2006, an invisible barrier was established at the Darién Gap, the jungle that straddles the Panama-Colombia border, to cordon the screwworm-free north off from the south. The barrier, as I observed when I reported from Panama several years ago, consisted of planes releasing millions of sterile screwworms to rain down over the Darién Gap every week. This never-ending battle kept the threat of screwworms far from America.
But in 2022, the barrier was breached. Cases in Panama—mostly in cattle—skyrocketed from dozens a year to 1,000, despite ongoing drops of sterile flies. The parasite then began moving northward, at first slowly and then rapidly by 2024, which is when I began getting alarmed emails from those following the situation in Central America. As of this month, the parasite has advanced 1,600 miles through eight countries to reach Oaxaca and Veracruz in Mexico, with 700 miles left to go until the Texas border. The U.S. subsequently suspended live-cattle imports from Mexico.
