By Mary Reilly-Kliss
Many Ozaukee Master Gardeners attended a special educational presentation concerning the Asian jumping worm (Amynthas agrestis) back in 2018 with Brad Herrick from the UW-Madison Arboretum. At the time, Brad was doing research on the worm, an invasive species with habits which alter the texture and make up of soil. The annual worm lives for one year, and then lays eggs in cocoons which overwinter and hatch the following year. The worm literally jumps, flipping itself up, over, and around when disturbed, and it was taking gardening news cycles by storm.
Though the worms may have a big effect on floral beds and the forest understory, they really don’t “do” much at a vegetable garden. They don’t eat root crops or tomatoes or carry off the lettuce. But, their presence was decidedly “creepy” for lack of a better word. Some of us at the Washington County Community Gardens (WCCG) did a mustard pour to make the worms come to the surface, and then we grabbed them and put them in buckets of vinegar. They died, and we dumped them in the neighboring corn field, feeling that we were doing something to stem the infestation. We saw quite a few worms in 2018 and 2019 but not many, if any, since and we didn’t know why.
So, I was very interested in Margaret Roach’s A Way to Garden podcast where she interviewed Brad last week to learn what, if anything, was new in the world of jumping worms. As it turns out, the worm which was originally discovered at the UW Arboretum in 2015, is still here, but now infests 38 states. The researchers have learned that years of drought lessen the appearance of the worms, but the cocoons are still there, waiting for wet weather to make their appearance. Eastern states have had a very wet growing season and so are seeing a resurgence of the worm, whereas we here are in a drought and are not seeing as many. BotaniGard a fungal application applied as spray or granules, has been shown to be a deterrent. Additional research is ongoing.
A transcript of the very interesting podcast is found here: https://awaytogarden.com/coping-with-invasive-jumping-worms-with-brad-herrick-of-uw-madison/
Here is a video of the worms in action at the WCCG. Probably pre-vinegar treatment.