An infested tree isn't killed right off, Arnold says. It's a slow death, normally occurring over two to three seasons. When a tree is stripped, the next generation of caterpillars move on. Oak is the favorite target, but the caterpillars will eat just about anything, including ornamental yard plantings, Arnold says. Chemical attempts to thwart the moths' spread have met with some success, and about 150,000 acres are targeted for spraying in West Virginia this year.
Scientists also see promise in a naturally occurring fungus that kills the caterpillars.
Still, it's a matter of time before Arnold, the Paul Revere of the insect world, runs out of counties to warn. That buys people a few more years, but once it's here, it's here.