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Jumping Worms That Destroys Soil Spotted In WI, 34 Other States

The invasive jumping worms spotted in Wisconsin can clone themselves as they chew away leaf litter and leave soil barren.

Several invasive species of worms originating from Japan and the Korean peninsula were introduced to Wisconsin and 34 other states. The worms can flip themselves up to a foot off of the ground, scientists said.
Several invasive species of worms originating from Japan and the Korean peninsula were introduced to Wisconsin and 34 other states. The worms can flip themselves up to a foot off of the ground, scientists said. (Courtesy of Rick Uldricks)

WISCONSIN — Several invasive species of jumping earthworms originating from Asia have been introduced to 34 U.S. states, including Wisconsin, and can chew away nutrients from soil and flip themselves up to a foot off of the ground, scientists said.

Amynthas agrestis, a litter-dwelling earthworm from the Japan and the Korean peninsula, was recorded as an invasive species to Wisconsin as early as 2017, data from the Centre for Agriculture and Bioscience International showed. Sometimes called Alabama jumpers, crazy worms and Jersey wrigglers, the worms are spread across the Eastern Seaboard, parts of the South and parts of the Upper Midwest.

The worms get their name because they "thrash around," USDA Forest Service soil scientist Mac Callaham said in a agency website post. "They can flip themselves a foot off the ground."

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While beneficial earthworms nourish soil, the invasive worms have the opposite effect: Amynthas agrestis can pose a risk to horticultural materials like soil, leaf litter, compost and mulch after they eat away the dead plant matter that new plants need to grow, CABI's description said.

Nightcrawlers and other earthworms "get elbowed out of the way" by the jumping worms, Iowa State University entomology professor Donald Lewis told KCCI. Jumping worms were found in 12 counties in Iowa.

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Jumping worms are parthenogenic, meaning they can reproduce on their own without a partner, according to the extension service at Iowa State. With the ability to clone themselves, jumping-worm populations grow quickly through a couple of generations a season.

They Engineer Their Own Ecosystems

Jumping worms are wreaking havoc with soil and, ultimately, the circle of life, Callaham told Sarah Farmer, a science writer for the Forest Service's Southern Research Station in Asheville, North Carolina.

Jumping worms expend a lot of energy, which they fuel by eating everything in their path. That includes leaf litter, the first layer of soil on the forest floor — home not only many unseen tiny creatures but also an important source of nutrients plants need to sprout and grow.
All earthworms feed on leaf litter, but jumping worms are "voracious," Callaham said.

"Soil is the foundation of life — and Asian jumping worms change that," the soil scientist continued. "In fact, earthworms can have such huge impacts that they're able to actually engineer the ecosystems around them."


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It's a conundrum for scientists, who say they need to learn more about the ecology of jumping worms before prescribing a management plan. The intelligence on them so far by about two dozen scientists was collected last year in a research paper detailing the second wave of jumping worm infestation in North America.

"We cannot really manage them once they are here," Andrea Davalos, an assistant professor of biology at State University of New York-Cortland and one of the authors of the research paper, told Upstate New York.

"There's no appropriate method to get rid of them," said Davalos, who also is a member of New York's Jumping Worm Outreach, Research & Management collaborative.

What Davalos and others have found in New York is that while jumping worms are widespread from Long Island to Ontario, Canada, their colonies are "very patchy." A colony of up to 30 jumping worms can live in a 2.6-square-foot garden plot, but a similarly sized space nearby may have none.

'Forestry-Wise, It's Disastrous'

Maine state horticulturalist Gary Fish told NECN, an NBC affiliate serving the Northeast, said his office has seen the number of reports of jumping worms increasing over the past five years and that their spread has been "a problem across the whole Northeast."

"Forestry-wise," he told NECN, "I would say it's disastrous."

Of particular risk, he said, are the maple trees in Vermont used to make syrup, and others used for wood products such as ash.

Similar stories emerge elsewhere across the country.

"Because of their ability to clone themselves, just one jumping worm can start a population, which makes them a different species to manage," Ryan Hueffmeier, an ecologist, environmentalist and professor in University Of Minnesota Duluth's College of Education and Human Service Professions, told KSMP, a Fox News affiliate in Eden Prairie, Minnesota.


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