As an early morning walker, I encountered a possessed worm here in Eden Prairie.
And so, a third case of an aggressively invasive species of worm, Amynthas spp., the so-called jumping worm, was confirmed on Oct. 1, 2021 in Eden Prairie. The jumping worm is known for its snake-like movements, rapid wiggling, and stripping of nutrients from forest floors and lawns.
The Eden Prairie reports on the jumping worm, which has the potential to completely alter the character, functionality, and make-up of northern forests, are documented here. To-date there have been 247 confirmed sightings in the state of Minnesota.
The most recent confirmed sighting was along the Minnesota River Bluffs LRT Regional Trail near Candlewood Parkway.
Oligochaetologists, aka worm scientists, note that Eden Prairie’s forests originally evolved without earthworms. European earthworms were introduced to the American continent. The last ice age pulverized worms and so the forests evolved alongside fungi, microflora, and fauna which slowly decomposed nutrient material for the forest floor.
In an August 2020 Minnesota Public Radio (MPR) article, Lee E. Frelich, director of the University of Minnesota Center for Forest Ecology, Fellow, Institute on the Environment, said he first spotted the jumping worm in Minnesota in 2006. He said he believed the jumping worm then went through a period of selection and adaptation before exploding across the landscape.
Jumping worm destroys soil, accelerates erosion, alters ecosystem
Frelich described the potential for destruction by the jumping worm in the MPR article, as horrific. “It will literally destroy the soil, altering the ecosystem at its most fundamental,” he said at that time.
Jumping worms can exacerbate the erosion of slopes in Eden Prairie, said Frelich. “Jumping worms turn the top two inches of soils into granules that are not connected and slide down slopes during heavy rain,” said Frelich.
Research into jumping worms and their impact on erosion is just starting. Frelich said the jumping worms’s effect on erosion is most prominent on north or east facing slopes, or forested slopes, and on loamy or silt loam soils.
Natural water seeps and springs impacted
“In other words, any slope with fine textured soil and where the soil temperatures remain cool and moist during summer,” according to Frelich.
Frelich said a change in soil structure by jumping worms could also impact natural water seeps or springs.
“Yes, the worms will reach higher populations in areas that stay constantly moist and have larger impacts there. They might possibly gather there from surrounding areas during droughts. This could lead to larger magnitudes of impacts,” said Frelich.
Conversely, he said, jumping worms are less likely to occur on sunny or sandy south facing slopes.
Jumping worm studies underway, guidelines available
The three confirmed cases in Eden Prairie indicate there are likely more jumping worms in the city, said Frelich.
Frelich, as well as Terrestrial Invasive Species Program Coordinator Laura Van Riper, Ecological and Water Resources Division, Minnesota Department of Natural Resources (DNR), pointed to guidance for Minnesotans to follow on the Minnesota DNR jumping worm webpage and the University of Minnesota Extension jumping worm webpage.
Panic is not recommended. Flailing worms with the capacity to turn soil into nutrient-stripped coffee grounds is alarming, but people can take action. They can be killed by placing them in containers with alcohol or in bright sunlight.
People should avoid purchasing jumping worms. Clean soil off of boots and equipment before moving them to new places. Follow the University of Minnesota’s recommendations regarding plant sales and plant swaps. Unwanted bait worms should be thrown in the trash.
A fungal isolate of Berauveria bassiana (commercially known as Botanigard), had a 60% mortality rate when used on jumping worms, according to the product’s label, noted Van Riper. Frelich said he was running trials with Botanigard at the University of MInnesota Arboretum as a potential control agent for jumping worms.
Funding for Frelich’s current research into jumping worms at the University of Minnesota is pegged at $299,254, according to the research website. Researchers will create a best management practice guide for jumping worm infestations in Minnesota.
There are other avenues for addressing jumping worms. For example, Frelich said nematodes are often parasites on earthworms and can reduce earthworm populations. “We do have nematodes in our soils in Minnesota. However, we do not have specific knowledge about their potential to prevent or reduce invasive jumping worms, and do not have funding to study this particular aspect of jumping worm biology.”