Recently we have received reports from homeowners about snake worms.
Snake worms (aka Alabama jumper, jumping worm, Asian crazy worm, or earthworms of the genus Amynthas in the scientific world) are named for their unusually active defensive behavior. The worms move very actively and wiggle a lot if disturbed, resembling snake movements. To make matters worse, the worms stay close to the soil surface, and are often found right under leaves and/or the upper soil layer. This behavior is not usual for other worm species and can be startling and visually unpleasant or disturbing to many people.
But this is not the only problem that crazy worms pose. They are an invasive species, originally from Korea and Japan, and they can cause significant disturbance in the forest ecosystem. The species is continuously introduced and re-introduced across eastern North America by the movement of horticultural and landscaping materials and use as fishing bait.
In Massachusetts we still do not know how damaging or disruptive this species may be for the turf and urban landscapes (lawns, golf courses, etc), but they have been found in high densities on several properties.
The species is active in summer, unlike many of the European earthworm species which are in the resting state during hot weather. Thus, this species avoids direct competition with the European earthworms and often is found as the sole worm species in a given area. Crazy worms usually have one generation per year in our region. Adults are sensitive to cold temperatures and die by the time winter sets in. Their “cocoon” (actually a sac that contains many eggs) can successfully overwinter, hatch in spring, and reach the resultant worms reach adulthood in summer.
Crazy worms can be identified relatively easily by their active wiggling and the pale, milky-white clitellum (band) which encircles the entire body about a third of the way back from the head.
No effective methods of suppression are known for this species. However, some measures can be taken to prevent the introduction of crazy worms to the area. Any organic matter product associated with horticulture or landscaping, including soil, leaf litter, compost and mulch can be a source of crazy worm invasion, so be sure to inspect materials before spreading on the landscape.
Not much is known about the species in Massachusetts, so if you have seen worms that are behaving strangely and suspect they might be crazy worms, please contact the UMass Turfgrass Entomology Lab, Dr. Olga Kostromytska, at 413-577-3997 or firstname.lastname@example.org.