In Loring Park, 2006, Jumping worms (Amynthas spp.) were first discovered in MN. Since then, they have moved through central and southern Minnesota landscapes at an alarming rate.

One reason for this is that jumping worms reach sexual maturity fast, allowing them to reproduce at a much higher rate than other worm species. They also process nutrients in the soil faster than traditional earthworms, creating the type of soil that resembles coffee grounds for which they are well-known. This loose soil easily washes away, which increases erosion potential. Unfortunately, this makes it difficult for many native plant species to establish. Oftentimes, this causes sites with jumping worms in MN to be dominated by invasive plant species.

Identification  

Jumping worms have many characteristics that help in their identification. As the name suggests, when handled, these worms tend to “jump” or violently thrash in an attempt to escape in a way that appears more snake-like than worm-like. They also have the ability to shed their tails, a trait commonly found in many lizard species.

Also, jumping worms are almost always found in leaf litter or in the first couple of inches of soil. Because they reside close to the soil surface, jumping worms have more pigmentation and a darker appearance than other worm species found in Minnesota.

The most effective way to identify worms in the Amynthas genus is to inspect their clitellum, a ring-like reproductive organ. Unlike other worms, their clitellum wraps completely around their body and is thinner, closer to the head, and lighter in color. 

Lastly, it is important to note that though a commonly held belief is that jumping worms are smaller than common earthworms, this is not the case. The multiple species of jumping worms in Minnesota vary greatly in size. They can be both larger and smaller than what we typically see in our backyards. 

Preventing the Spread

Unfortunately, there is no research-based method for removing jumping worms once they have infiltrated a site. For now, taking the proper steps to prevent their spread is the only way we can reduce the spread of this invasive species. 

The most common way that we see jumping worms spread is through transportation of improperly heated compost. When in need of compost, we at Natural Shore work with companies that heat their compost to a minimum of 131°F and turn their piles on a regular basis. This will kill both adult jumping worms and their eggs.  

For fishing enthusiasts, avoid purchasing worms labeled something you don’t recognize. This is especially true if they are advertised as “snake worms”, “Alabama jumpers” or “crazy worms.” And, even when purchasing angle worms or nightcrawlers, make sure to properly dispose of any soil or extra worms in the garbage.

Also, always use caution when transporting any type of soil. Be careful when accepting plants as gifts, as invasive worms may be tagging along. And never never introduce worms into your soil.  

New Research

On a positive note, researchers are beginning to take a critical look at this invasive worm species in Minnesota. They are addressing questions, like: How do jumping worms spread in Minnesota? Does temperature limit their spread? Is commercial treatment effective? What are the current best management practices? Check out this recent U of MN study to learn more: Jumping worms in Minnesota. 

As new information becomes available, it will undoubtedly strengthen how we all deal with this invasive species. We believe that it is important for individuals, organizations and companies to be aware of the risks and take actions to prevent their spread. With timely education, prevention, and management, we can all work to reduce the environmental impacts from the pesky jumping worms.