It may have made for the perfect lesson, but it was a discovery that no invasive species expert wants to make.
During a workshop on invasive species last October, University of Wisconsin-Madison Arboretum leaders took students into the field to show them, theoretically, how to survey for invasive species.
But as a Wisconsin Department of Natural Resources invasive species expert was explaining how the ground would change if a specific species of earthworms was present, the class got a much more realistic lesson than they were expecting.
“We went out to the woodlands and Bernie (Williams) was telling them about this Asian worm that we’re on the lookout for, but that’s not here yet. And then there it is, jumping and snaking around,” said Brad Herrick, an ecologist at the arboretum.
It was the first confirmed sighting of Amynthas agrestis in Wisconsin, although it’s been found in the Southeast and East since it was reported in the southern Appalachians in 1993.
The worms, also known as "jumping" or "crazy" worms, can be inadvertently transported to the United States from their native Japan and the Korean Peninsula along with imported landscape plants.
The fear of the jumping worm in a new habitat is that the forest floor will become barren, reducing the regeneration of trees and making it more hospitable for other invasive species.
“This particular invasive worm is very large and aggressive, and it reaches maturity very quickly,” explained Monica Turner, a University of Wisconsin-Madison zoology professor. “It eats its way through the soil faster than other earthworms.”