Watch Out for Jumping Worms

Spring is a good time to watch out for jumping worms (Amynthas sp.), the latest invasive pest to hit Minnesota. As gardeners are planting potted plants, adding compost and mulch to gardens and spending more time observing their yards, they are more likely to notice the writhing jumping worms and the tell-tale soil with a coffee-grounds texture that is a sign that this new invasive is with you.

While jumping worms have been in Minnesota since at least 2006, the Minnesota Department of Natural Resources is now considering listing it as a prohibited nonnative species, which would make it illegal to possess, import, transport or distribute jumping worms without a permit. The worms are not widespread, but they are making inroads in Minnesota. To gather more information on the problem, the University of Minnesota is asking gardeners to report their encounters with jumping worms.

What is a Jumping Worm?

This pest is one of several species in the genus Amynthas. It goes by common names such as Alabama jumper, Jersey wigglers, snake worms or crazy worms. The names come from the worm’s tendency to wiggle and jump wildly when disturbed.

The worms live in leaf litter or the first few inches of soil. They overwinter as cocoons and are able to survive even our cold winters. The worms have a smooth, light-colored ring around their bodies. The easiest way to identify them is by behavior and by what they do to soil. Their eating and waste excretion results in soil looking like coffee grounds. Serious infestations can lead to soil erosion and damage to plant roots and beneficial soil fungi and microbes.

Jumping worms move around in compost, mulch and potted plants, and the best way to control this pest is to prevent their spread.

Recommendations for Gardeners

If you get a bad infestation of jumping worms, there is not much you can do. However, preventing them from getting into your garden can be done with some extra diligence.

The DNR recommends the following for gardeners:

  • Don’t purchase worms advertised as “snake worms” or jumpers. If you practice vermicomposting, be sure the worms you purchase are not contaminated by jumping worms.
  • Buy potted plants from trusted sources and examine the soil around the plants carefully for the coffee-grounds texture or signs of worms or their cocoons.
  • When possible, plant bare-root plants or use seeds for starting your garden.
  • If you see a worm, take its picture and share it with the DNR or the University of Minnesota, then dispose of the worm in the trash or by solarizing it or soaking it in isopropyl alcohol. Do not put it in your garden or compost pile.

Other pests we’ve heard about lately include magnolia scale, our old friend the Japanese beetle and brown marmorated stick bugs.

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