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Conservation Commission

Posted on: November 2, 2023

What's Up with Jumping Worms?

Jumping Worm (Adult) Twitter Size

The Conservation Commission would like to share information about jumping worms. We have all heard of invasive plants and insects, such as glossy buckthorn and the emerald ash borer, and the problems these species cause for the health of our forests and trees, but another threat is below our feet: jumping worms. While common earthworms are also non-native invasive species in our part of the world, jumping worms appear to be having a much larger negative impact on our environment. Living in the upper 6 or so inches of soil, they devour organic material and leaf litter, leaving behind bare soil that is vulnerable to erosion and compaction. When they invade natural areas, such as forests, they interfere with regeneration of native plant species. In vegetable gardens they may interfere with germination and survival of seedlings and nutrients availability, stunting plant growth.

“It’s not entirely clear how the jumping worms have spread. Conventional knowledge holds that they can’t cover much ground on their own—perhaps 30-odd feet in a year, although one researcher I talk to swears he’s seen a single worm move that far in an afternoon. Their cocoons, which are about the size of peppercorns, can be carried much farther in water, and scientists have noticed that invasions often march down hillsides and along waterways. But experts suspect that the blame lies primarily with humans. It’s all too easy to unwittingly transport worms and cocoons in plants, mulch, and soil, in the treads of shoes and tires, or caked onto landscaping equipment.“ from The Atlantic.

So what can we do?

1. Learn to recognize jumping worms, their castings, and their cocoons. We’ve included a few photos here, but you can find many more at the links provided. 

2. Stop the spread! 

  • Sell, purchase or trade only compost and mulch that was heated to appropriate temperatures and duration following protocols that reduce pathogens. The adult worms will not survive the winter, but the cocoons will. Heating compost to >105 F will kill worms and cocoons. Only share bare root plant material or cuttings unless you know that jumping worms are not present in your garden. 
  • Carefully inspect garden materials for signs of jumping worms or castings before bringing products home and introducing them to your landscape or garden. 
  • Be especially careful when sharing plant material at community plant sales/swaps. The cocoons are hard to see and are the only sign of jumping worms early in the year.
  • Jumping worms are occasionally sold as fishing bait or for use in vermicomposting. Do not purchase them for these purposes, or any other purpose. 
  • Do not dump yard waste of any kind in natural areas. This can accelerate the spread of jumping worms if the yard waste contains cocoons or adults of the jumping worms. 
  • Arrive clean, leave clean! Remove soil and debris from vehicles, equipment, footwear and personal gear before going to and from work and recreational areas.

3. Consider reporting your observations on iNaturalist.

4. Try not to panic.

More Resources:

Adult Jumping WormJumping Worm CocoonJumping Worm Castings
Adult jumping worm. The clitellum (the pale ring) completely encircles the adult worm, but is not a reliable distinguishing feature in immature jumping worms. Photo: Olga Kostromytska, Stockbridge School of Agriculture.
Cocoons of jumping worms, only a few mm in diameter. This is how they overwinter!! Photo: Marie Johnston, University of Wisconsin-Madison Arboretum.
Jumping worm castings along Mink Brook in Hanover NH in 2023.

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