Note: The above was determined to be an ordinary earthworm - sedate and almost sleepy when I lifted it from the soil in my blueberry patch.
Jumping worms have been in the US for quite some time, imported to the US probably on plant roots. However the recent concern has arisen because they seem to be spreading quite rapidly at this time. They resemble the "normal" earthworms and nightcrawlers which we are accustomed to seeing in the garden. It is interesting to note that earthworms are not native either. Because they can be helpful in speeding the decay of humus (decomposing leaves and other plant material) into soil nutrients, we have come to think of them as beneficial.
The difference with jumping worms is that they tend to appear in much greater numbers and have voracious appetites. This can create soil devoid of all nutrition affecting plant growth. These worms are likely to be devastating to the forest landscape here in Vermont as it is dependent on very slow decay which consistently feeds the many native plants and trees. Areas where they have invaded show a lack of low growing plants in forested areas. Some groves, such as hemlock stands, are naturally devoid of low growing plants, so look for a change from the norm.
As a gardener, jumping worms can cause slow growth, plant failure and reduced harvest. They can also destroy the earthworms and nightcrawlers to which we are accustomed.
A first sign of jumping worms can be an unusual texture of the soil, which looks like coffee grounds. This is the worm castings (poop). You would also likely note an absence of bits of decaying matter - bits of grass or other decaying matter that you typically see in your garden.
If you are digging, pulling weeds or harvesting root vegetables and see a worm that is more active than the normal earthworm, you can suspect it is likely a jumping worm. I have developed the habit of picking up any worm and having a look at it before deciding it is benign.
Jumping worms are often present in numbers in an area. Pick the worm(s) up by hand or with your trowel and place in a container. Relax, take your time and have a good look. These worms are not poisonous nor can they hurt you so there is no need to be nervous about handling them. They are pretty good climbers so don't leave them in an open container as they can escape pretty quickly.
When disturbed by a touch, a jumping worm will thrash around. This is the most identifying feature of jumping worms. A regular earthworm may move but with a slower, sedate movement.
Examine the worm closely. On a jumping worm, the clitellum (band of tissue near the head which contains reproductive organs) closely encircles the entire body. In an ordinary earthworm, it is raised and is only on top.
Jumping worms often arrive on plant roots. Purchase bare root plants and grow your own vegetable and flower seedlings if possible.
You can wash potted plant roots in three changes of water but because the eggs are minute, it can be difficult to be sure you have eliminated all of them. Also, the eggs may still be present in the wash water, so your wash water could spread them wherever you dump it. Heat is the only known way to kill the eggs (100 degrees +) for several hours.
Don't buy worms advertised as jumping worms, crazy worms, snake worms, Alabama jumpers for any purpose. When buying worms, ask!
Watch carefully for jumping worms and the coffee grounds texture in any material You are considering for addition to your soil. They love compost, manure, leaf litter and mulch because of the high volume of organic matter.
Solarize bags of potting soil by leaving them in full bright sunlight for 3 days. Temperatures above 100 degrees will kill the worms and eggs.
Solarize compost by laying down a tarp. Place material 4 - 6 inches deep on the tarp. Pull in the edges and add another tarp, tucking the top tarp under the bottom one. Leave for 3 days in full sun.
Solarizing in the garden can be helpful in killing eggs, but the worms likely just leave the area if they find it too hot.
If possible, take photos and video and also photos of the soil where you found them.
Place in a tightly sealed plastic bag and either leave it in the sun or place it in the freezer. Then discard the entire bag in the trash.
Drop them into alcohol, vinegar or water mixed with a squirt of dishsoap.
It won't completely solve the problem, but can help to control the population in that any you kill will not reproduce.
Solarize the area where you found them:
Solarizing probably won't kill adult worms as they will probably just move on to a cooler area. But it will kill eggs. The adults will die over winter.
Solarizing is likely most effective in the spring because the adults will be dead and the eggs unhatched. But solarizing the area can help at any time to reduce the number of eggs.
To solarize the area, cover the area with clear plastic and leave it there in the heat of the sun for 3 weeks.
Upload photos of jumping worms you find to inaturalist.org to help track the invasive species.