Question: There is a new invasive species of earthworms found in Oregon that I’d like to know about.
Answer: A new invasive earthworm species called a Jumping Worm is causing alarm. Jumping Worm refers to three similar species of worms: Amynthas agrestis, Amynthas tokioensis and Metaphire hilgendorfi. The most aggressive and widespread in the United States is the Amynthas agrestis, but all incur similar environmental damage, and all are cause for concern if discovered in the Pacific Northwest.
Gardeners generally welcome earthworms into their gardens as they help to increase the amount of air and water that gets into the soil. They help to turn the soil, bringing down organic matter from the top and mixing it with the soil below. They break down organic matter, like leaves and grass into things that plants can use, increasing decomposition, and creating usable nitrogen. When they eat, they leave behind castings that are a very valuable fertilizer.
The invasive Jumping Worm is thought to have been brought to North America in the 19th century with plants and other imported agricultural materials. Since then, the worms have spread widely. Jumping Worms are insatiably hungry and leave behind loose, granular soil the texture of coffee grounds.
This altered soil can no longer retain moisture, lacks nutrients and quickly erodes, jeopardizing gardens and forest ecosystems, researchers report. Jumping Worms are considered extremely invasive because they can reproduce without mating, proliferate quickly and lay eggs that resemble the soil.
Resembling the more common European nightcrawler, the Jumping Worm is slightly smaller, a brownish color rather than pink, and appears sleeker and smoother. Their clitellum (color-like ring) is white in color and constricted.
They are also known as “crazy worms”, “Alabama jumpers” and “snake worms” because they thrash and snap their bodies like a rattlesnake when touched or held, and are remarkably fast. They can even spring into the air and shed their tails to escape.
A useful fact sheet on jumping worms can be found at bit.ly/3wqJXPx.
Consider following these simple steps recommended by Oregon State University to reduce the spread of Jumping Worms:
- Do not buy Jumping Worms for composting, vermicomposting, gardening or bait.
- Monitor your garden for Jumping Worms and their unique soil signature
- Avoid introducing organic mulch or soil from outside sources
- Plant bare root stock or seeds when possible
- If you have Jumping Worms remove and dispose of them and monitor your plants for drought and root loss.
Jumping worms can spread when gardeners move soil, landscape plants, sod, mulch or compost. In addition, earthworms such as red wigglers (Eisenis fedida) purchased for composting or European nightcrawlers (Lumbricus terrestis) used for fishing bait may be contaminated with Jumping Worms.
Do you have a gardening or insect question? Contact the Douglas County Master Gardeners via email at [email protected]. Douglas County Master Gardeners are trained volunteers who help the OSU Extension Service serve the people of Douglas County.