Much to the dismay of local gardeners, a new invasive species known as jumping worms has recently been detected in Wausau. Jumping worms are a type of earthworm that is native to Asia. They most likely arrived in the United States in the late 1800s in soil that was imported with plants or agricultural goods. Movement of plants or soil is still the main way that these worms invade new areas. Jumping worms were first detected in Wisconsin in 2013 at the UW-Madison Arboretum and, since then, they’ve become well-established throughout much of southern and eastern Wisconsin. The recent discovery of these worms at several locations in Wausau, including the Monk Botanical Gardens, marks their first detection in Marathon County.
Jumping worms look somewhat like nightcrawlers, but they behave very differently. Nightcrawlers tend to burrow deep into the soil, and often wriggle gently when handled. In contrast, jumping worms tend to stay close to the soil’s surface and wriggle vigorously when handled, in an almost snake-like fashion. Although no earthworms are native to Wisconsin and all earthworms feed on dead plant material and other organic material found in soil, jumping worms reproduce more rapidly and consume soil organic material much faster than our existing earthworms. As a result, jumping worms have the potential to significantly reduce the quality of soil for the healthy growth of plants in both natural and cultivated areas, and to make the soil more prone to erosion.
Since these worms were discovered in Wausau late last month, a small group of Master Gardener volunteers, as well as Monk Botanical Gardens volunteers, have been collaborating to better educate themselves about this new threat. The group has reached out to staff at the UW-Madison Arboretum, the Wisconsin DNR, and other botanical gardens to learn more about the pest and possible ways to deal with the worms once they are onsite and reduce their spread. One interesting finding is that these worms are often present for some time before being detected, and so are probably more widespread than official records would suggest. As a result of these conversations, the Master Gardeners have invited Brad Herrick, UW-Madison Arboretum ecologist, to Wausau, to share his jumping worm expertise with the public. Brad’s presentation will be from 6-7:30 on October 7, at 212 River Drive in Room 5. There is no charge for this event thanks to funding from the Northcentral Wisconsin Master Gardener Volunteers, but pre-registration is required. A flier with an agenda and registration information can be found at https://fyi.extension.wisc.edu/marathonmg/files/2019/09/Jumping-Worms.pdf