Yes, I have jumping worms. They appeared suddenly in my compost heap and quickly proceeded to process all of the mulch and wood chips in my garden. It was an alarming discovery to say the least. My neighbors reported them as well. I don’t know where they came from, but I suspect a big decomposing fiberglass bait pool left on my property by the first owner may have been the source. I never saw worms in it, but it was full of similar castings.
Problems:
1) They DESTROY mulch. I use leaf litter and wood chips as path mulching in my garden. With the worms, this has limited benefit as all mulch is turned into castings within a season.
2) The castings are poor. Unlike night crawlers, jumping worm castings are large and limited to the top organic layers of soil. They do not enable root systems to develop, wash away extremely easily and are not intermixed with the other soil horizons. Whatever nutrient gain is realized is short and offset by a plant’s struggle to establish itself. I have noted tillering, stunted/no growth, uprooting when plucking fruits or leaves, etc. I also suspect the worms eat the young rootlets as they develop, further stunting growth.
To make matters worse, we had enormous amounts of rain this summer, with intense downpours of several inches multiple times over the summer. I have dealt with unprecedented erosion, with literal streams developing and cutting course through my garden - lasting for days. The top inches the soil being jumping worm castings and loss of mulch
made matters somehow even worse.
3) Chickens do not like them. The birds are fearful of the worms. One bird was enthusiastic at first, but I think she ate so many of them that they continued to writhe inside her and made her feel unwell. After day one she has turned up her beak at them.
In short - they are awful. I can absolutely see why forest ecologists are worried about their spread in northeastern forests. They absolutely will limit seedling regeneration and soil development. I will try solarizing large parts of my garden to reduce populations next summer, which will require some extra planning for planting schedules. Good luck if you become cursed with these freaky varmints.