What the heck are jumping worms?

Jumping worms feed in the top soil layers and decompose soil even faster than other worms

Worms are meant to crawl and slither … aren’t they? Then how come some are jumping?

We’re all familiar with earthworms, which can be quite large but essentially always look alike. They’re pinkish and look sort of like small snakes.

Gardeners among us will also recognize wrigglers, which are small, bright pink worms that favour compost and richly organic soils.

Earthworms are known for improving the quality of the soil where they live and feed. Through their feeding cycle, they filter soil, add nutrients to it and break down organic matter, leaving a better quality soil behind.

Or do they?

Regardless, the benefits to all soil-dwelling organisms are significant and far-reaching.

Flash forward to the modern-day, and we find a new intruder: the jumping worm.

What the heck is a jumping worm?

Actually, this is a collection of many species, not just a single one. They’re known collectively as jumping worms because when threatened, they thrash from side to side to confuse or repel predators. They don’t actually jump, but their thrashing can be quite dramatic and can last for up to 30 minutes.

First found in the late 1800s in Wisconsin, they were likely brought in through the Asian horticultural plant industry. They then spread widely as they’re prolific breeders and adaptable feeders. The first recorded instance of jumping worms in Ontario was at the Ojibway Prairie near Windsor in 2014. Since then, their presence has been confirmed in Toronto, Hamilton and Wheatley. Typically a garden-dwelling critter, they’re known to move into natural habitats.

So what’s the big deal? Don’t we want these creatures to make our soil better?

All worms, including the 17 known species of jumping worms in North America, decompose detritus and other plant materials at a rate exceeding the capacity of the ecosystem. So although we think they’re the best thing to happen to soil, all worms actually upset the balance and make the soil poorer in quality rather than better.

Jumping worms feed in the top soil layers and decompose soil even faster than other worms. The outcome is the soil becomes structurally different and nitrogen-rich. The waste produced by the worms (called castings) is pebble-like, making the soil more porous so water runs off rather than remaining to be absorbed by plants. Likewise, the texture of the soil is such that plants have trouble developing strong roots, so they are weaker than if worms not been present.

What do jumping worms look like?

The best time to search for them is in August and September as they are quite big (up to 13 cm long) and often occur in large numbers. The soil, as mentioned, will have a pebbly appearance.

The worms themselves will be similar to the earthworm we’ve always known, but the clitellum, a smooth band that encircles the body, is cloudy white to gray in colour.

They have noticeably large mouths, which can actually be seen by the naked eye when the worm is examined.

While they can break off tail segments to thwart predators, the underlying and easiest identifier is their thrashing movements.

In April and May, young jumping worms hatch from egg-filled cocoons that resemble mustard seeds after overwintering in the soil. Over the next two months, they feed and grow; by August, they’re reproductively mature. Then they mate (but can also produce eggs without a mate) and lay their eggs in the soil to repeat the cycle. Most of the adults will die each fall, relying on the eggs to start the next generation the following spring.

So what should we do?

They’re here, and we really can’t ever eliminate them. But some diligence when buying or transporting plants should help quell the spread of this dangerous new component of our ecosystems.

For more information, check out this Oregon State University site. If you see any of the worms, report your finding to https://www.eddmaps.org or call the Invasive Species Hotline at 1-800-563-7711.

So let’s get hopping and find some worms!

Geoff Carpentier is a published author, expedition guide and environmental consultant. Visit Geoff on LinkedIn, Instagram and Facebook. For interview requests, click here.

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