Asian Jumping Worms is a term given to at least five species of invasive worms, mostly in the genera Amynthas and Metaphire. Jumping worms were unintentionally introduced to North America from East Asia, likely through infected nursery stock.
While they are now widespread throughout much of the US, they have only recently been documented in northern hardwood forests in WI, MN, and NY States
Often, earthworms are considered beneficial to soil health. This is true to a small extent for European earthworms, but is definitely not the case for invasive Asian jumping worms. Asian jumping worms reproduce twice as fast as European earthworms, and consume soil organic matter so effectively and fast that soils are degraded tremendously. Plus, jumping worms are toxic to birds, amphibians, and to other worm species.
The loss of leaf litter, and the erosion and subsiding of soils which result from a jumping worm infestation leads to greatly reduced forest regeneration and a loss of biodiversity across trophic levels including amphibians, birds, beneficial fungi, and understory plants. Jumping worms create bare soil in the forest, which paves the way for unwanted invasive plants such as garlic mustard and buckthorn. Watch a short video to learn more.
Asian jumping worms do not need to mate, and a single one can start a whole new population. They are easily spread through the movement of nursery stock, compost, topsoil, well as gardening and landscaping equipment and shoe treads.
Jumping worms will thrash wildly when handled. Click here to view a video of this behavior.
Clitellum (band near the head)
The clitellum completely encircles the body, is milky white to gray, and smooth to the body (not raised). The common non-native European species have a raised, reddish clitellum.
Granual soil that resembles coffee grounds is a sign of an Asian jumping worm infestation.
Currently, there are no methods known to control earthworms. Therefore, preventing their spread is most important. Below are some precautionary steps that can help slow their spread.
- Buy bare root stock when possible and be wary of sharing /moving plants.
- Do Not buy/use jumping worms for bait, vermicomposting or gardening.
- Only buy compost that is heat treated.
- Thoroughly clean garden tools, shoes, and vehicles.
Surveying for Asian jumping worm:
The best time to find jumping worms is late August or September when they have reached an adult size. Search underneath leaf litter above the soil in forested and urban areas.
If you find Asian Jumping Worms:
Note the location in which the worm was found.
Take close up photos of the specimen. Be sure to include a close up of the band around the body of the worm (clitellum).
Report sighting to iMapinvasives.org or your local Cornell Cooperative Extension.
You can check your property for Asian jumping worms by using a mustard pour.
Title photo by Susan Day / UW Madison Arboretum
Asian worm clitellum photo by Wisconsin Master Gardener, European worm clitellum photo by Holger Casselmann
Granular soil photo by Bernadette Williams/ Wisconsin DNR
Mustard pour photo by Karen Ceballos, NY Master Naturalist Program Assistant, Cornell Department of Natural Resources