Jumping worms — the invasive, soil-wrecking earthworms — are turning up in more corners of Minnesota, and researchers with the University of Minnesota are racing to map how far they've spread.
The worms were first documented in the state in 2006, when researcher Lee Frelich spotted Amynthas agrestis in Minneapolis's Loring Park. Two decades later, they've spread across the Twin Cities metro, into Rochester and southeastern Minnesota, and possibly as far as Duluth.
Ryan Hueffmeier, a research, outreach and education specialist at the University of Minnesota Duluth who has spent 15 years on the university's Great Lakes Worm Watch and Jumping Worms projects, said the worms' feeding habits reshape soil in ways that ripple through entire ecosystems, threatening plant growth and soil biodiversity. His research is funded by the Minnesota Invasive Terrestrial Plants and Pests Center.
The university's Jumping Worms Project is asking Minnesotans to photograph suspected sightings and submit them through EDDMapS, the web-based invasive species tracker; verified photos become official, geotagged reports researchers use to trace the spread. After mapping infestations in garden beds on the Twin Cities campus and at the Minnesota Landscape Arboretum, researchers suspect mulch — especially mulch that hasn't been heat-treated — is a major way the worms move from yard to yard.
The tracking effort comes as local governments confront active infestations. Ramsey County halted mulch and compost distribution from its yard waste sites after jumping worms turned up at its Arden Hills site on June 28, with the county keeping distribution paused statewide within the county as it works with the Minnesota Department of Natural Resources to assess the situation.