Jumping for Joy? Not so much....

Earthworms: the hidden workhorses behind fertile soil and beautiful plants. While cruising the interwebs recently, I came across an article about some worms that I'd never heard of before: Japanese Jumping Worms. There are three species currently recognized that share this common name: Amynthas agrestis, Amynthas tokioensis, and Metophire hilgendorfi.  They are also called Crazy Snake Worms, Wood Eels, Alabama Jumpers, and Jersey Wrigglers. These worms are considered to be highly invasive; they can reproduce without mating, and their eggs are very difficult to see in soil. Their presence is not to be taken lightly, however. They are more voracious eaters than their European counterparts, decimating the layer of decomposing material that is necessary to support plant and animal life. They also feed on plant roots, which can kill garden and nursery plants.

Although these worms are relatively new to California, they have been found in pots and in the ground in the northern regions of the state, and will most likely find their way down to the Bay Area given some time. These invasive worms are worrying environmental scientists, because they pose a threat to forests and can harm biodiversity in gardens, nurseries, and parks. Below are some common questions about these wiggly pests:

How do I tell the difference between Japanese Jumping Worms and Nightcrawlers?
This is a great question, as these two worms look pretty similar. Nightcrawlers are lighter in color, and have a reddish-pink band (called a clitellum) that sits like a raised saddle on their bodies. The clitellum on jumping worms is lighter in color (whitish), surrounds their bodies completely, is flush with the rest of the body, and their bodies are darker in color. Reference the photos below for a visual comparison of these two worms:

Nightcrawler

Jumping Worm

These worms also differ in their habits. When picked up, earthworms will attempt to get back to the ground, but are slow-moving. Japanese Jumping Worms, on the other hand, act almost like snakes do, writhing quickly and making 'jumping' movements.

Will I be able to tell if there are Jumping Worms in my garden?
Jumping Worms can be found in the surface soil or just below - higher in the soil profile than Nightcrawlers. They mass together, and because they reproduce so quickly and in such great numbers, you'll be able to identify them visually if you come across a colony. A neat trick to perform is to pour mustard water (mix a gallon of water with 1/3 cup of ground yellow mustard and shake) over your garden soil in a few areas. The worms will come to the surface, and you can collect them and see if they are indeed Jumping Worms. You'll also be able to witness their behavior and differentiate it from that of regular earthworms. These worms are most active during the summertime, in mid-June these worms will be entering their first season of maturity. This is when you'll be most likely to notice their presence. Another sign that these pests may have invaded your space is that the soil texture will be similar to coffee grounds.

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​The soil texture in the photograph here is an indicator of the presence of Jumping Worms.

​How do I get rid of these pests?
​If you find Jumping Worms in your soil, don't panic. Your first step is going to be to educate yourself about these critters, and let others around you know that you've located some in your garden. Next, you may want to dig up the colony of worms and the surrounding soil to remove both the worms themselves and their eggs. Place the removed worms and soil in a black plastic bag and leave it out in the sun. This will kill both adult and cocooned worms. You can toss the bag in the trash afterwards. Make sure to clean off any tools and gear you use when working in your garden frequently and thoroughly, as the tiny eggs can be spread on trowels, shovels, shears, and even gardening shoes and clothing. A final step in ridding your space of Jumping Worms is to heat moistened soil to a temperature of 104 degrees Fahrenheit. This will kill any cocoons in the soil, wiping out the next generation of worms. This task can be accomplished by spreading clear polyethylene over the area and allowing the sun to act as a heat source. Leave the plastic out for 2-3 weeks; in this time the soil should reach the target temperature.

What are some best practices to ensure that I don't inadvertently bring these worms into my garden?

1. When purchasing dirt or compost, ensure that it has been heated to a temperature of at least 130 degrees Fahrenheit for at least three days. This is a preventative measure to stop the spread of many garden pests that many reputable producers will perform. 
2. Clean your garden tools and gear regularly to stop the spread of these worms in your own garden.
3. Only bring potted plants in to your garden that have come from reputable nurseries. Sharing plants with other home gardeners can be risky, as most home gardeners do not go to the same lengths to ensure their product is pest-free.
4. If you have a gardening service taking care of your property, talk to them to see what their practices are for cleaning their equipment and gear. If you are not satisfied, have a collection of tools and other gear available for them to use on your property that you are responsible for cleaning and maintaining.
5. Contact the California Department of Fish and Wildlife to report your sighting. The required documentation and further instructions can be found on this webpage:

Report an Invasive Species Sighting

The invasive Jumping Worms are in California now, and are working their way down the state. Keep an eye out for these destructive garden critters, remove them from your soil and destroy them, and report your sighting(s). If we garden responsibly, we may just be able to slow the spread of these pests (and others) in our state. As always, thanks for reading! See the references section below for more information on these worms.

Until next time!

​Kristi.

REFERENCES
Cornell Cooperative Extension: Invasive Asian Jumping Earthworms
​Invasive Jumping Worms found in Northern California Gardens, Potted Plants. Here's What to Do.
PDF: Jumping Worms FAQ
Invasive Jumping Worms Have Made Their Way Into California, and Scientists Are Worried