Earthworms have long been heralded as a gardener’s best friend, as revitalizers of the soil. While this is certainly an apt description of tried-and-true composting worms such as the Red Wiggler, not all earthworms deserve such glowing praise. Take the Alabama Jumper, Amynthas agrestis.
Alabama Jumpers are not your garden variety earthworms. Hailing from Asia, these invaders are surface-dwelling consumers of leaf litter that have turned up everywhere from suburban backyards to deep within the Great Smoky Mountains National Park. They are known for flipping wildly when disturbed (hence their common name) to the point where they can jump out of your hand with ease. Such unique traits often make these worms familiar to those gardeners and composters who have encountered them.
The Alabama Jumper shares few of the composting virtues that mark its more familiar European cousins. Rather than staying put in compost piles, Alabama Jumpers will wander off at the slightest provocation. Once in the wild they consume beds of leaf litter, or “duff”, which might have taken decades to build up. Leaf litter is an important resource to many native plants and animals, and its removal has been shown to have harmful ramifications which echo throughout our forest ecosystems.
So why are Alabama Jumpers cause for concern among horticulturalists? By virtue of moving soil from one place to another, the horticultural trade can facilitate the passive spread of invasive earthworms. A single Alabama Jumper stowed away in a potted plant can go home with a customer and start a new infestation.
During a 2011 survey of Cincinnati area garden shops, I observed that some shops were infested with Alabama Jumpers while others were not. I collected data in order to determine which factors might be behind this uneven distribution, and used statistical modeling to detect any trends. The analysis showed that Alabama Jumpers thrived best in garden shops that drew their stock from outside of the Great Lakes region, and in shops which had their stock displayed over moist soil. Displaying pots over soil provides a perfect habitat for these worms as they travel in and out of pots’ drain holes in search of food.
“Lag time” is often cited as a reason why invasive species are able to wreak such ecological havoc: we sometimes don’t realize that an invader is present and causing trouble until their populations are so entrenched that it’s too late to turn the tide. Alabama Jumpers do not yet slither and jump throughout all of Ohio’s woodlands, and so we still have an opportunity to limit their spread through informed management strategies. While the horticultural trade is not the only manner in which these worms are spread, addressing the issue here is a logical and inexpensive place to start.
To learn much more about the Alabama Jumper and how its spread can be controlled, attend a free lecture at the Civic Garden Center on Monday, October 8 at 6 pm.
— by John P. Gorsuch, guest blogger and UC undergraduate student