With 5,000 or so species of earthworms wriggling about the planet, a few are bound to be nastier than the rest. So is the case with Amynthas agrestis, aka the "Asian crazy worm" or "Alabama jumper," an invasive pest found in Japan, Korea, and—for five decades—in the eastern and southeastern US. Now that they've turned up at the University of Wisconsin-Madison's arboretum, and then alarmed scientists by surviving the area's harsh winter, there is growing concern about what might happen should the worms work their way beyond the property. The worms get their "crazy" nickname because, unlike many earthworms, they wriggle and even jump—not to mention eat—voraciously. They also propagate rapidly, reaching maturity in only 60 days and reproducing without a mate.
They're now covering about an acre of the arboretum, and staff there are washing boots and tools carefully in an attempt to halt the worms' spread. As Scientific American explained in 2009, a glacier eliminated all native earthworms from the Great Lakes region some 10,000 years ago, and the forests evolved without them; now, those who invade the area—as discarded bait, trapped in tire treads, or imported via mulch, perhaps—are leaving forest floors barren. "Our native plant communities developed without the presence of all these hungry worms," an arboretum ecologist tells UWM News. "The Amynthas eat so much that they take away the spongy, surface organic layer that those plants need for nutrients." (Check out which pest has recently found its way to New York.)