Wildlife

Jumping Worms: The Creepy, Damaging Invasive You Don’t Know

October 31, 2016

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Photo © Susan Day / UW Madison Arboretum

Disturb a jumping worm and it’s like a nightcrawler on steroids: It violently writhes on the forest floor, recalling a snake in a bad horror movie. Try to catch it, a piece of its tail will detach in your hand — still wriggling as you hold it.

But put aside the creepy factor: jumping worms may be the next big threat to northern forests.

Jumping worms, consisting of various non-native species from multiple genera, have become established in a number of eastern and southeastern states. In 2013, species from the genus Amynthas were confirmed for the first time in the Upper Midwest, at the University of Wisconsin-Madison Arboretum.

In the forests and prairies of the Upper Midwest, the jumping worm could significantly alter habitats and decrease biodiversity. Why are they so damaging? And is there anything we can do to stop them?

Why Much of What You Know About Earthworms is Wrong

You probably learned about the wonders of earthworms at an early age. They aerate the soil. They help your garden grow. And they catch fish. The humble earthworm is a creature to celebrate.

Photo © Susan Day / UW Madison Arboretum
Photo © Susan Day / UW Madison Arboretum

Overlooked in all this earthworm love is an important fact: in a significant portion of the North American continent, no native earthworms have existed since before the Ice Age. As such, forests and other habitats have evolved without them.

But people love earthworms. They indeed use them by the millions for fishing, and for composting, and to help gardens grow. And so the worms have been spread far and wide. Even areas with native earthworms have largely been taken over by non-native varieties. The common nightcrawler — familiar to anyone who has ever cast a bobber and hook — is a European species.

Earthworms have also spread into the northern habitats where worms have been absent for thousands of years. The hype is true: earthworms cycle through a lot of refuse, and fundamentally change the soil. This may be good in your backyard garden plot, but it’s not in the northern forest.

“Earthworms change the environment to suit their needs,” says Brad Herrick, ecologist and research program program manager at the University of Wisconsin-Madison Arboretum. “When they are introduced, they make a host of physical, chemical and biological changes to the soil environment.”

Essentially, worms turn the forest floor — a complex community of plants, invertebrates and microbes – into a completely different habitat.

The jumping worm, if established in the Upper Midwest, brings new threats. “We think the changes to native habitats will be similar to other earthworms but even more dynamic,” says Herrick.

Spread of the Jumping Worm

You probably think of earthworms as living underground. But the jumping worm actually lives in the topmost layer of the forest floor — amongst the fallen leaves and other material that cover the soil. It eats that fallen organic material. And that’s the problem.

That leaf litter provides essential nutrients to the forest. Trees need long-lasting sources of nutrients. When jumping worms quickly turn leaves into very loose soil (resembling coffee grounds), they deprive trees of essential nutrients.

They thus can inhibit the establishment of tree seedlings. The altered soil is inhospitable to many  native plant species. And that soil also disrupts the relationships between fungi and trees.

In short, the jumping worm could have profound effects on the overall forest ecosystem.

As with so many invasive species, they’re adaptable and difficult to stop. They’re parthenogenetic: they can reproduce without fertilization. The introduction of a single individual is enough to launch a jumping worm invasion.

The worms have an annual life cycle. They die in the fall, but leave tiny cocoons that spend the winter in the soil.

And they can be spread readily by human habits. Take their preferred habitat of fallen leaves. At this time of year, many people are raking leaves into a pile and setting them by the road to be picked up or converted into mulch. The worms — or their cocoons — are thus transported to new habitats. Compost and potted plants can also move the worms around.

“Unfortunately at this time, there are no good control measures,” says Herrick. “The important thing now is to the stop the spread. Everyone can help.”

Stop the Jumping Worm

Herrick and other conservationists agree that prevention is the most effective tactic. If you live in the Upper Midwest, and see a writhing, snake-like earthworm in your backyard, report it to your state natural resources department. (In Wisconsin, you can email invasive.species@wi.gov  to report sightings).

The Wisconsin Department of Natural Resources also has a handy identification card to help you distinguish the jumping worm from the common nightcrawler.

Wisconsin DNR also suggests examining potted plants and gardening and landscaping materials for the presence of jumping worms. If you are doing landscaping and gardening work, be sure to clean your equipment and clothing to prevent transporting cocoons.

And if you buy compost, only buy from sources that heat the compost at appropriate temperatures and duration to kill pathogens.

The jumping worm is not yet established in much of the northern United States. The time is now to keep it from becoming the next invasive species horror story.

Matt Miller

Matt Miller is director of science communications for The Nature Conservancy and editor of the Cool Green Science blog. A lifelong naturalist and outdoor enthusiast, he has covered stories on science and nature around the globe. Matt has worked for the Conservancy for the past 14 years, previously serving as director of communications for the Idaho program. More from Matt

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49 comments

  1. Great reporting and keep up the good work. We need more reports like these that are science-based. It does make me wonder what the next ecological horror will be.

    1. Then perhaps you might consider that you are not paying close enough attention to give a darn about the future of forests? The natural world is complex and nuanced. We need to understand that to save ourselves.

  2. Listen, you may be right about this worm but I am WAY more worried about Trump’s impact on the environment just now! Thanks you the interesting info though!

    1. I hear you! But please, take a deep breath and go outside…refuse to let the politics intervene with good work you can do in your own back yard 🙂 Good luck…I wake up in the AM feeling like I have an elephant sitting on my chest…oh wait, I do!

  3. It would be great to know what nematodes and viruses are possible controls.
    We have serious invasive slug problems too, and many of them eat duff and seedlings. They too might be controlled with nematodes.

  4. I had a horrific experience with these worms a few years ago in Florida. My husband and I returned from a trip and found a terrible stench in the house when we entered into it again. I followed the smell and thousands of these worms were hanging from the sliding door frames and writhing on the patio and had entered through the tracks of the sliders into the house. It was a horror movie!! I callled everyone I could think of to help, even the police. No one had ever heard if a similar event. Our house was on a large property adjacent to a golf course, lots of acreage and soil all around our home. No one came to help. My husband and I had to overcome our revulsion and nausea and sprayed the worms pesticides and 409 and had to hose them off the sliding doors and tracks and tile stone floor in the living room and outside on the patio. My poor husband used a shovel to place them in plastic bags and sealed those and disposed of them. They never appeared again after that , but it was a nightmarish experience.

  5. Can these worms live in an environment where we may not get a hard freeze for a couple of years, like here in the Pacific Northwest? Where did these worms originate?

  6. I deliberately placed worms in my earth 30 years ago because of poor soil, now it is richer and turned dark. Everything grows better.

    1. There are about 2,700 species of earthworms, each of which is evolved to live in a specific place, with its own parasites and predators. Pick one up and plop it down somewhere else and it has the potential to act as a disease with no checks. Without the population controls where it came from, there is nothing to keep the population from being a problem. This is why invasive species are such so difficult and expensive to deal with…oh and the is that problem when people don’t understand the impacts of what they are doing…like the person who introduced English sparrows, or the road engineer who thought Rosa multiflora would be good along the road sides.

  7. I have learned so much from reading from your blog. I find the more I learn the more I want to learn about the interesting, exciting, and concerning environmental issues that affect our world. Thank you so much because I want to know even more.

    1. I have the same question
      Red wigglers were given to me by gardening program for use in a worm bin. Some have escaped into my garden.

  8. Are there any native predators that would be effective in controlling spread of the Jumping Worm?

  9. I live in Virginia. Are there reports off jumping worms here? Where may I gol for information?
    Thanks

  10. According to the Wisconsin DNR these worms are native to SE Asia. Great article, but I was itchin’ to find out where they came from.

    1. Thanks for saving some of us the time and contributing to the conversation in a constructive way.

  11. I am part of a conservation and restoration group here in Oregon, and I see how damaging this could be. Thank you for this information!

  12. Unfortunately, I met the jumping worm late this summer. I was turning over my “working” compost pile and discovered a large number of hyperactive worms writhing around. I live on the east side of Madison, WI. I’m not sure what the method of their introduction to my property was, but I have now found them in one of my raised beds. They have also spread to my other two finished compost piles. I tried black plastic bagging them in the sun for several weeks, but it did not kill them. And of course, there’s the cocoons still in the soil. I hope researchers come up with a remedy for these pests. These are not the worms we’re used to!

  13. We recently discovered these near our home in Northern California. They are clearly different from the typical worms we have seen here before, and can jump up to two inches if touched in attempts to move them.

  14. I noticed many garden snacks in my garden during summer time , but i also noticed this gum- pin worm
    in late October . Thanks for art. and info. this was unpleasant to see this ,I will give them sugar with baking soda on start.

  15. I hope the invasive group will address the ongoing feral/roaming cat problem, if they haven’t already, and how Trap-Neuter-ReIMPOSE programs don’t work.

    1. First, my thanks go to the author for the heads-up on the worms, another gift from Asia (here in western NY we’re in the hot zone of Emerald Ash Borer, another gift from that part of the world).

      And yes, Maja, I would like to see free-roaming cats officially classified as “invasive” so proper control (i.e. removal) can be implemented. The fact that this hasn’t occurred is because it’s a political hot-potato. Don’t hold your breath.

  16. Why is this a problem now. Where are they native to.They will most likely not survive due to the millions of gallons of Roundup sprayed on our plants and leaves.

  17. Things have gotten so out of hand with so many non native species in various parts of the United States. It is hard to keep track of them all. Now there’s the threat of jumping worms.

  18. Maybe we should allow burning of leaves again. Would that help destroy the worms?

  19. yea so if I see it what do I do with it? report it I will for sure But how do I rid myself of it in the mean time?

  20. Thanks Matt for the heads up. It appears prevention of disease in any life cycle is the first step.

  21. In NJ, I’ve come across worms that act as “violently” as these but never saw them dislodge a piece of their body and don’t know they are indeed jumping worms. Have they been found in NJ?

  22. Great article Matt,

    Any news if these worms have made there way into Northern Virginia? If so, any way of combating it naturally?

  23. Good reminders for all of us. There are 30,000 invasive species in the U.S.A. causing $148 billion in damages/year. Thank you for the excellent reminders.

  24. Thanks so much! I will share your film with the crew of volunteers that work at my church

  25. Hello Matt,
    This is a new one for me, jumping worms. Thanks for the tip of heated compost. Could we send some to congress and Donald Trump Daily Show? Do you think they could survive his bluster?
    This is a bad time for science and conservation in general with DT in charge. He doesn’t venture into the wilds. But I am glad you do and are walking in Aldo Leopold’s footsteps . I wish you well and hope you continue all you do in good health for all of us.
    Darla Rae Duffy
    Pittsburgh, Pa.

  26. This article was extremely informative. I never knew that worms could be bad for the environment.

  27. Just wondering if there is a plotted map where these things are, and if there are any efforts to control them. I am beginning to realize that “closed systems” with as little input from the outside is the way to go…I still buy plants but not until I am now doing more with seeds. And when I bring a potted plant home, it is only AFTER I have researched its potential invasiveness in my area and three others with the same climate conditions. I remove the dirt before planting the plant, rinse it off in a gravel area, and solarize it (dry as a bone too).

  28. These are being sold on the internet as good vermicomposting worms. What is the difference in a Red Wiggler, African Nightcrawler, or the Alabama Jumper? Can we still use the Red Wigglers for vermicomposting?

  29. Finding this worm in your yard and reporting it is a first step. No one has made any suggestions about how to manage your yard after a positive identification. I am facing this. I would like to know what recommendations there are for pasturizing compost since this will be the vector for spread in my vegetable garden.

    1. Hi Jane, The red worms are definitely different and the EPA is recommending them for composting: https://www.epa.gov/recycle/how-create-and-maintain-indoor-worm-composting-bin Because of the overlap in common names, I’m not sure about the Alabama Jumper, however, from the description in the link you share, it sounds like they “dig deep”, which is a different behavior than the invasive Asian Jumping Worm that primarily stays near the surface. Thank you!

  30. Very interesting. I first heard about this worm in a newspaper article earlier this spring. Now I know that the worm I found while digging in .y stones to plant a bush was indeed a red jumping worm.

  31. I think I have a problem in my garden with these worms. I live in NY 50 miles north of Manhattan on a deciduous wooded slopped acre. Ever since I moved into my house, and observed the massive amount of worm castings around my flower beds, it appeared that there was too much worm castings and not enough to hold the soil together. My soil is also dry with shade. How to I identify the worms to know if I have the Asian jumping worm? Thank you.

  32. Just heard a news report that jumping worms were found in the county in which I live in central Wisconsin. There was little information given there but I then found this page. Good information but it needs to be made more public. When our forests are gone they will take more than our lifetime to replace, if possible. I am surprised at the sarcasm and childishness of many of the comments here. One person brought up an idea that I wondered about too; how about burning? Then again, I doubt many people could be trusted to do this in a safe manner, as demonstrated by their responses below. I have been in a battle all summer with Japanese beetles and feel I am losing this important fight, since they will soon dig down into the soil to overwinter. The weather has been cold and in my city, dry as a bone. In early summer we had a terrible storm that destroyed a large number of mature trees throughout the city. The news about jumping worms feels like piling on. I will be waiting to hear of a solution that I can try in my little piece of heaven. It will take a large effort by many people to make a difference. So far there has been no urgency or concern among my neighbors where Japanese beetles are concerned.