Healthy Food Delivery : Jumping Worms Are Invading Gardens

If you’re a gardener, you know worms are good for the soil — at least in most normal situations. They’re an important part of the ecosystem; that is, when they’re in their native ecosystem. Recently, an invasive worm known as a ‘jumping worm’ has been identified. Much like the spotted lantern flies that have garnered attention in the past few years, this jumping worm invasion is spreading across the country. Unfortunately, that doesn’t bode well for the habitats it’s affecting.

What Are Jumping Worms?

According to information put out by Michigan State University (MSU), jumping worms are a type of earthworm indigenous to Japan. As they’ve moved into more and more of the United States, they’ve picked up several names, including “jumping worms, Alabama jumpers, disco worms, Jersey wrigglers, crazy worms, snake worms and even wood eels for species found inside rotting logs.”

According to MSU, these worms have several distinguishing features, including:

snake-like movements with thrashing when disturbed
mature length ranging from 1.5-8 inches (4-20 centimeters)
smooth, glossy skin with a pale, whitish ring (the clitellum) that completely encircles the body
large mouths that can be readily seen

MSU notes that a key difference between a jumping worm clitellum and that of a “naturalized worm” is that a jumping worm’s is “usually flat against the skin, rather than raised, occurring 14 to 15 segments after the worm’s head, versus 23 to 32 for naturalized worms.”

The MSU information also warns that “they can lose the ends of their tails when grabbed to escape capture.” So be prepared if you’re trying to catch one to study, or round them up to remove them.

Why Are Jumping Worms Bad?

If other earthworms are helpful for the environment, what makes jumping worms so dangerous? MSU explains that “activities of jumping worms change characteristics of the soil and alter the soil surface, destroying habitat that is important for native insects, ground nesting birds, and other small animals.” The key way this happens is through worm manure known as castings.

According to the MSU post, jumping worms “immediately begin feeding on leaves and decaying matter on the ground, disrupting plant roots and soil mycelium, which is an important part of healthy soil.” When they do this, they convert all of that matter into castings.

Unlike naturalized earthworm castings, which typically stay underground, jumping worm castings are more commonly found on the surface. This means that “the nutrients in the castings are not available for plants to use.” Instead, it “may be carried away in runoff after it rains.” MSU warns that “without a protective layer of mulch, the nutrients are eventually lost.”

This leaves behind “soil that is less fertile, less able to retain water and more susceptible to erosion.” As a result, “these conditions make it difficult or even impossible for some native plants and local wildlife to survive.” They also “make the land more prone to colonization by other invasive species that are tolerant of poor soil conditions.”

Additionally, while naturalized earthworms have factors that keep their population in check, jumping worms do not have “significant predators or other population controls on this continent.” Add this to their “voracious appetite and rapid reproduction without the need to mate,” and you’ve got a recipe for a takeover.

How to Tell if You Have a Jumping Worm Infestation

MSU says that “if your mulch is disappearing at a faster-than-normal rate, and the soil looks crumbly like used coffee grounds, jumping worms may be present.” According to their post, the best way to check for an infestation is to “look in damp, shady areas and scratch around the leaf litter and soil or look under logs and rocks.”

If you want a faster approach, the university also suggests that you “mix 1/3 cup of ground yellow mustard powder with 1 gallon (3.5 L) of water and pour it over a 1-foot (30 centimeters) square of soil.” The post explains that the mustard is an irritant to the worms, and they’ll come up to the surface to escape it. If you do find jumping worms, it’s crucial that you report them to your state or regional invasive species network right away. This way, their spread can be tracked.

How to Remove Jumping Worms from Your Yard

If you know that you have an infestation, MSU recommends a couple of different strategies to help. You can try to kill the eggs with a process called solarization. To do this, wait for a stretch of warm and sunny weather. Then, “spread 2-6 mil, clear plastic sheets over the soil and bury the edges to keep them in place.” MSU says that “studies indicate that cocoons will die in three to four days if the weather is sufficiently warm and dry.”

Another option is tilling your soil. You’ll want to do this in May, “when it is warming and worms have hatched, but before they are old enough to produce cocoons.” As you till, you’ll likely kill some of the worms and unearth others. The ones you find, you can destroy by “putting them into a plastic bag and leaving it in the sun for several days. You can also drop them into a container filled with vinegar or alcohol.”