Issue 2, May 5, 2021

Jumping Worm Update

Jumping worms were first identified in Illinois in 2015. These invasive earthworms have been confirmed in several counties across the state, and observations suggest eggs can overwinter in warmer parts of the state. Jumping worms are native to East Asia. They have been sold in the United States as bait under the names crazy worm, Alabama jumper, and snake worm. The worm has characteristic coloration and behavior. Adult worms are approximately the same size as other naturalized earthworms, but are much darker. Most of the body is dark gray or brown, with a milky white or light gray band of tissue (the clitellum) circling the body. The clitellum is smooth, compared to other species where the clitellum is raised compared to the body. When disturbed, jumping worms become very active, wriggling and thrashing vigorously.

Figure Jumping worm identification features

Jumping worms are voracious consumers of organic material, which can affect soil quality. Organic matter in the soil is converted to earthworm casings, giving the top layers a grainy structure that looks like dry coffee grounds. This affects the soil structure, availability of nutrients in the soil, and soil water holding capacity. In turn, these changes can affect plant growth.

They breed quickly and eggs survive Illinois winters. Adults reach maturity in approximately 60 days, allowing populations to double during the growing season. These worms are also capable of reproducing without mating. There are concerns about the effect these worms will have on native areas, ornamental plantings, and agronomic fields. The worms have been identified in several U.S. states, including Wisconsin (2013) and Indiana (2015). From reports from Wisconsin, it appears that these worms are most damaging in areas without other established earthworm populations.

Management consists of preventing the spread of these invasive worms. Recommendations to prevent the spread of jumping worms and their eggs include cleaning equipment before moving to another site, reducing the transportation of mulch and soil, and carefully inspecting nursery plants before installing them in a new landscape. If soil is infested, maintaining organic matter through fertilization and mulching may help reduce the adverse effects of the worms.

For more information, please see: https://extension.illinois.edu/news-releases/keep-eye-out-jumping-worms-gardening-season

Fact Sheet: https://extension.illinois.edu/sites/default/files/jumping_worms_factsheet_04152021.pdf

Author:
Diane Plewa

Return to table of contents