Worms are meant to crawl and slither, aren’t they? Then how come some of them are jumping?
We are all familiar with earthworms, which can be quite large but always look alike. They are pinkish in colour and look sort of like a small snake. Gardeners amongst us will also recognize wrigglers, which are small bright pink worms which favour compost and richly organic soils.
Earthworms are renowned for improving the soil quality where they live and feed. Through their feeding cycle, they filter soil, add nutrients, 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 modern-day, and we find a new intruder, the Jumping Worm. What is a jumping worm?
Actually, this is a complex of many species, collectively known 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 thirty minutes.
First found in the late 1800s in Wisconsin, they likely were brought in through the Asian horticultural plant industry but then spread widely, as they are prolific breeders and adaptable feeders. The first record for Ontario was at the Ojibway Prairie near Windsor in 2014. Since then, they have been confirmed in Toronto, Hamilton and Wheatley. Typically, a garden dwelling critter, they are known to move into natural habitats. So what’s the big deal? Don’t we want these creatures to make our soil better?
Actually, all worms, including the 17 known species of Jumping Worms in North America, rapidly decompose detritus and other plant materials, at a rate exceeding the capacity of the ecosystem.
So although, we think they are the best thing to happen to the soil, all worms actually upset the balance and make the soil poorer in quality than better. The 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 and therefore makes 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 had worms not been present.
What do Jumping Worms look like? The best time to search for them is in August and September, as then 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 which encircles the body, is cloudy white to gray in colour. They have noticeably large mouths, which the naked eye can actually see if the worm is examined. While they can break off tail segments to thwart off predators, the underlying and easiest identifier is the thrashing movements mentioned above.
In April and May young Jumping Worms, which overwinter in the soil, hatch from egg-filled cocoons, which resemble mustard seeds. For the next two months, they feed and grow and, by August, are reproductively mature. At this time, they mate and lay their eggs in the soil to repeat the cycle. They can also produce eggs without a mate. Most adults will die each fall, relying on the eggs to start the next generation the following spring.
So what should we do? Well, they are here, and really we cannot 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 https://extension.oregonstate.edu/gardening/techniques/how-avoid-spreading-invasive-species-plant-sales-or-plant-swaps, or if you do find any of them, report it to https://www.eddmaps.org or call the Invasive Species Hotline 1-800-563-7711. So let’s get hopping and find some worms!
Geoff Carpentier is a published author, ecotour guide and environmental consultant. Visit Geoff online on LinkedIn and Facebook.