Invasive 'crazy worms' threaten trees in the Northeast, could hurt maple syrup production

A crazy worm, distinguishable from common earthworms by the
clitellum, a band around its body (University of Vermont photo)

"Earthworms are often seen as a welcome presence in gardens, and even on fishing hooks. But in the Northeast, experts say invasive 'crazy worms' from Asia are creating havoc in forests — and they say the unusual worms are a danger to animals and plants, and especially to sugar maple trees," Bill Chappell reports for NPR.

Crazy worms, also called jumper worms for their wiggly nature and propensity for jumping right out of your hand, "reproduce rapidly. They also love to tear through the nutritious layer of decomposing leaves and nutrients that blanket the forest floor — a habit that can be very damaging to forests, including maple trees," Chappell reports. "Plus, they alter the composition of the soil, creating a texture that's often compared to coffee grounds. The modified soil is ruined for many native plants, as it's stripped of vital nutrients and prone to increased erosion."

The worms are present in other areas of the U.S., but the Northeast is particularly vulnerable to them because the last Ice Age left it with no native earthworms. Common earthworms have since populated the area, and crazy worms have been around since the 1800s, but it wasn't until recently that their numbers became a problem. Crazy worms resemble common nightcrawlers but are smaller.

"The worms mainly spread within the U.S. through the domestic market, both through the horticulture industry and through their sale as fish bait," Chappell reports. States such as Maine and New York have banned them, but scientists haven't yet found a way to control them. Part of the problem, one scientist said, is that worms' benign reputation makes it difficult to find someone to fund the research.