They live underground, have a voracious appetite, damage the local ecosystem, and what’s more, they can throw themselves up to a foot in the air.
It’s not a creature from a sci-fi novel. It’s one of Michigan’s invasive species. They have many nicknames, including crazy worms, snake worms, wood eel, Jersey wigglers, and Georgia jumpers, but most commonly, they are known as jumping worms.
This species of worm is native to Japan and the Korean peninsula. They were first discovered in American soil in the late 1800s, said to be brought over from Japan in the root balls of decorative plants, and their numbers have spread ever since, stretching across 34 states so far.
Michigan confirmed the species living in the wild as recently as 2008, first found by Professor Scott Tiegs in the Oakland University Biological Preserve. The Michigan Department of Natural Resources (DNR) says the species may be widespread in the Lower Peninsula.
Their most distinguishing behavior is their thrashing, writhing, jumping, and sometimes snake-like motion, hence the name.
While they look similar to earthworms, they have distinctive key visual differences. Jumping worms have a flat, milky white clitellum (or a wide ring or collar) that is located closer to its head and circles all the way around their bodies while earthworms have a raised, reddish-brown clitellum closer to the middle of their bodies.
Jumping worms are infamous for consuming organic matter at a breakneck pace, eating leaf litter in the upper levels of soil, absorbing nutrients upon which plants rely, and “ out-competing native species, including insects, salamanders, ground nesting birds and other earthworms,” according to officials.
The organic waste they leave in their wake changes the composition of the soil, says the DNR, making it less favorable for natural fungi, plants, and bacteria to thrive. The granular waste they produce, which looks similar to coffee grounds, doesn’t retain water and makes the soil more likely to be washed away, which negatively affects plant regeneration wherever they can infest, including gardens, yards, potted plants, compost, mulch, forests and agricultural fields.
The soil disruption caused by jumping worms can create more opportunities for invasive plants to move into the ecosystem, say experts at Cornell University.
Presently, there is no proven method of control or pesticide management to deal with jumping worms as a population. There is no way pragmatically to treat all the soil in the state, and there is currently no program to stop them.
Environmentalists, however, say you can kill them individually. The best known method is placing them in a sealed plastic bag before freezing it, heating it, or sending it to a landfill.
If you find jumping worm cocoons in your mulch, soil, or compost, which are 1-2 millimeters and laid during the winter, it is recommended to heat it to 130F for at least 3 days to destroy the cocoons.
A common method to draw jumping worms to the surface is the mustard pour, which involves mixing one-third of a cup of ground mustard seed with a gallon of water and pouring half the mixture on the ground a few square feet at a time, waiting a few minutes, then applying the rest. The mustard pour does not hurt the organisms in the dirt, but it does force jumping worms to the surface.
Tempting as it is to use them as fishing bait, experts recommend against it since they can easily escape a bait can and spread to a new environment.
The DNR is asking everyone to report any jumping worms to the Midwest Invasive Species Information Network. In the meantime, purchase only new soil and mulch, and clean your shoes, vehicles, and gear before moving site to site, lest you too spread this illusive invasive species.