Farmers, nursery owners and wildland managers should be on the lookout for the invasive jumping worm this spring as it becomes more active in the Pacific Northwest, experts say.

The pest first arrived in the region six to eight years ago, said Sam Chan, an Oregon State University watershed health and invasive species specialist. They’ve been found around cities, gardens, small farms and parks along the Interstate 5 and Columbia River corridors.

“These probably were brought in initially as composting worms or bait, because even though this is an invasive species, in some places you can still actually buy them online,” Chan said.

The pest is spread through garden activities and composting.

“It doesn’t really do what other earthworms do, in that they churn the soil,” Chan said.

Instead, the jumping worm devours organic matter near the surface, leaving a dry, coarse, coffee ground-like material that is impervious to water, creating erosion and large pores in the soil that expose roots, making them more susceptible to cold and heat.

So far, the impacts in Oregon are localized, Chen said. They’re found in gardens, where gardeners have had difficulty establishing plants.

They haven’t spread to farms and wildlands yet, but that becomes increasingly likely, he said.

The jumping worm is “innovative,” going dormant into a cocoon stage when the weather is too cold or too warm, Chan said.

They’re still dormant with the colder winter weather, but will likely become more active in mid- to late spring, he said.

If farmers see an earthworm with a very distinct thrashing motion — “earthworms typically aren’t able to do that” — they should contain the area and not move the soil, because they could spread the pest, Chan said.

If nursery owners find it in their stock, they should not sell those plants, Chan said.

Gardeners should monitor their plant purchases carefully. Plants known to come from an infested area should have their roots washed and put in a new pot with fresh soil.

Some mustards and fertilizers irritate or kill the worm, but there really aren’t any products labeled to control it, Chan said. The labeling process would require more demonstration, and registration could take several years.

“The key is to avoid the hotspots,” Chan said.

Jumping worms haven’t yet been verified in Washington state, but there are “suspect spots,” said Todd Murray, director of the Washington State University Puyallup Research and Extension Center and executive board member of the state invasive species council.

Samples can be sent to the WSU plant diagnostic lab for identification, he said.

The council plans to offer more education about the jumping worm and other invasive species, Murray said.

Most of the earthworms in the region aren’t native to the area, Murray said.

“This is another one that’s an exotic worm that’s likely going to be part of our landscape,” he said. “This is just another added insult to the native earthworm fauna that we do have.”

https://puyallup.wsu.edu/plantclinic/