The forest is a treasure of biodiversity and a giant carbon sink – Copyright AFP/File Wojtek RADWANSKI
For most gardeners, an earthworm is great for the soil, however, there is an invasive earthworm in North America that is quite literally, destructive.
According to the U.S. Department of Agriculture, there are over 9,000 species of earthworms in the world, and while many of the slimy wigglers are good for the environment, the Asian jumping worm, Amynthas agrestis, is definitely not one of them.
The Asian jumping worm is native to Japan and the Korean Peninsula and was introduced to North America during the early 19th century. They became a problem, specifically in the Southern United States, during the 1920s and 1930s.;
CBS News is reporting that the invasive species was originally brought from Japan to the Bronx Zoo in the 1940s to feed platypuses. Since then, they’ve spread slowly but steadily to dozens of US states, most likely hitching rides in mulch, compost, and potted plants.
The worms are also known as crazy worms, snake worms, Georgia jumpers, Jersey wigglers, and sharks of the earth, but whatever anyone calls them, they do have a voracious appetite.
According to The Guardian, the invasive species was first spotted in Wisconsin and across the New England area in 2013 and was identified in California’s Napa county in July.
The hermaphroditic worms grow to roughly eight inches (20 centimeters), have a dark body and a milky white band, and “are distinctive for their theatrical behavior,” writhing so much that they can flip themselves up to a foot off the ground.
“These earthworms are extremely active, aggressive, and have voracious appetites,” the California Department of Food and Agriculture (CDFA) warned in a report. “True to their name, they jump and thrash immediately when handled, behaving more like a threatened snake than a worm, sometimes even breaking and shedding their tail when caught.”
Worms wreaking havoc in Canada
The worms can devastate the top layer of leaves and soil on a forest floor, causing erosion and preventing native plants from taking root. Perhaps nowhere is that threat more serious than in Canada, per the Walrus.
Michael McTavish is an expert in earthworms and conducts postdoctoral research at the University of Toronto. Up until August of 2021, McTavish had only seen the Asian jumping worm in pictures and videos.
In August last year, McTavish responded to a Facebook message from gardeners in some Toronto and Hamilton neighborhoods, who were reporting an unusual presence in the soil. He soon found himself standing in one of those gardeners’ yards with an unusually energetic worm in his hand and a sinking feeling in his heart.
Researchers fear the invaders could transform up to half of the country’s sensitive boreal forests, not only harming native plants but also releasing excess carbon dioxide that would otherwise remain trapped in the soil.
To make matters worse, nearly all earthworms in Canada are considered to be invasive because most of the native species were wiped out in the last ice age. Canadian environmentalists know it’s hard to make the public care, but they hope the dramatic behavior of jumping worms can draw attention to the wider problem.