The Colorado potato beetle is a notorious pest—and a kind of unstoppable genius.
The modern pesticide era began in the 1860s when Midwest farmers started killing these beetles by spraying them with a paint color called Paris Green that contained copper arsenate. The beetles soon overcame that poison as well as lead arsenate, mercury DDT, and dieldrin—and over fifty other pesticides. At first, with any new chemical, many beetles are killed—but none of them last for long. The beetles develop resistance, usually within a few years, and continue merrily chomping their way through vast acres of potatoes in farms and gardens around the world.
Scientists have a poor understanding of how this creature turns this trick. Current evolutionary theory, focused on DNA, falls short of explaining the rapid development of pesticide resistance. While the beetle shows a lot of genetic variation, new DNA mutations probably do not show up frequently enough to let them evolve resistance to so many types of pesticides, so fast—over and over.
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