Jumping Worms

Impact – An aggressive Asian earthworm and a relatively new invasive species but spreading rapidly across the US, causing major forest ecosystem disturbance. They are ravenous feeders that consume the organic matter and strip the soil of nutrients which then may be unable to support plant growth. Altered soil may not retain moisture. When such a disturbance happens, it provides an opportunity for other invasive plant species to move in. European earthworms which benefit the soil are now being displaced by this destructive worm.

What are / How to identify – These worms, which can reach six inches, live in leaf litter, organic matter and the top few inches of the soil. The adults are an annual species and die after the first freeze. Their cocoons, ~ size of a mustard seed, survive the winter and hatch in mid-April. Cocoons can survive winter temperatures but the hatchlings cannot survive freezing temperatures.

One telltale sign of infestation is a very uniform, granular soil created from worm castings often compared to coffee grounds. When they are disturbed, they thrash about with an erratic snakelike movement. On close up examination, you will observe a prominent milky white to light gray band which completely encircles and is flush with the body. It resembles European nightcrawlers but their band is raised and reddish-brown in color. The cocoons are very small and hard to see.

Control – Once an invasive is established it is difficult to remove as is the case with these. The focus should be on prevention. Consider reducing the amount of organic atter you add to your garden. Check any plants for the distinctive coffee ground like soil. You will need to remove the worms and cocoons. If you have a small population, hand pick and destroy adult worms by bagging or drowning in water with a small amount of bleach. To assist in handpicking, make a solution of 1/3 cup dry mustard / 1 gal. water and drenching the area which will irritate the worms and bring them to the surface where you can easily remove them. Research is ongoing. Abrasive materials such as biochar (ground up charcoal and diatomaceous earth has shown some promise in killing adults. Incorporate one of these into the infested soil. Also, an organic fertilizer called EarlyBird has been effective but may need two applications- one in late April/early May to target the hatchlings and again in summer. Anglers -dispose of unwanted bait worms in the trash.

More info: https://extension.psu.edu/look-out-for-jumping-earthworms