Asian Jumping Worms: Another Forest Foe

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- Hi, Sanford Smith here from Penn State Extension.

Today, we're going to talk about an unusual topic.

It's Asian jumping worms.

Perhaps you've never heard of them but you're going to find out more about them in this video.

With me, I have Michael Skvarla from Penn State.

He's an entomologist.

Michael, what is an Asian jumping worm?

- So Asian jumping worms are an invasive worm that was introduced from Asia in the late 1800s.

They were initially restricted to the Southeast, in Georgia and Alabama, but in recent decades have been found across the Eastern United States, in Wisconsin in the Northeast and also across Pennsylvania.

- How'd they get that crazy name, jumping worms?

- Well, compared to things like European earthworms that most people would be more familiar with, night crawlers and those kinds of worms, Asian jumping worms are very active.

So if you poke them, if you pick them up, if you dig them up, they flail all about.

It's a defense mechanism against predators and it gives them their name.

They'll flip all around.

- Okay, I got it. - It's very obvious once you've seen it. - Right.

What's the problem with Asian jumping worms?

Why should the listeners of this video be interested or concerned about this?

- So, Asian jumping worms consume leaf litter and organic material.

So, leaf litter is just the leaves and the sticks and the things that you find on the forest floor.

They consume that at about twice the rate compared to European earthworms.

And so that habitat that the leaves provide for insects and spiders and snakes and all kinds of animals that live on the forest floor disappears.

It also changes nutrient cycling.

So Asian jumping worm castings, the poop, they are small and hard when they dry out, and so they don't reincorporate into the soil of the forest.

They lock those nutrients up and make them unavailable to trees and other plants.

And so that can affect forest regeneration.

You get a lot less small seedlings and herbaceous plants in forests that have Asian jumping worms, because the nutrients just aren't there for them, when they were there before Asian jumping worms.

- So, quick question here.

You mentioned how they compare with European worms.

Why are you doing that?

What about our American worms?

- So, here in the Northeast areas that were glaciated, that were covered by glaciers during the last Ice Age, have very few native earthworms.

- Okay.

- Primarily, the ones that we do have are restricted to forested habitats, and you'll find them under logs and under bark of fallen logs.

But all of the earthworms that you find out in a lawn in urban areas, in developed areas, all of those are introduced.

They're not native, they're primarily from Europe.

Think about when Europeans came over, they brought ballast in ships that was primarily rocks and dirt, and dumped it off so they could pick up trade items here and then sail back to Europe.

All of those worms came in, all of that ballast, and spread throughout previously glaciated areas.

- Yeah, right, okay.

While Asian jumping worms aren't native, almost none of the worms that people are going to be familiar with are native either.

- Sure.

We're saying there's a lot of different species of worms, aren't there, and that kind of blows most people's minds 'cause they think all worms are created equal, right?

- There are, there's probably 40 to 60 species of worms in Pennsylvania in the Northeast.

There's a lot.

- Wow, that's amazing.

So, what can you do to avoid this problem?

And I will say this that where I've seen jumping worm damage, there's nothing on the forest floor, there's no leaves left, there's no little plants.

It's really a very serious condition if a forest has these jumping worms in it.

But what can people do to prevent that problem?

- So, in most of the Northeast, Asian jumping worms are restricted to areas around homes.

So they're moved in mulch, in other organic material that you bring in for things like planting beds around your house.

So, the first thing you could do is just not bring those materials onto your property.

If you do have to bring those kind of materials in, then you can treat them.

Asian jumping worms die at about 104 degrees Fahrenheit.

So if you cover that mulch or that organic material with a clear piece of plastic for a couple days and let that solar radiation heat it up, that will kill all of the jumping worms in there.

And then you can incorporate into your landscape without moving jumping worms around.

The other thing you can do is not use Asian jumping worms for a fishing bait, and not, don't leave your earthworms go if you are using live bait at the area that you're fishing.

Don't just dump your worms out at the end of the day.

- Sure.

Make sure you take them home and discard them in a place that they're not going to get out into the landscape.

- Sure, right, okay.

And you mentioned once to me that there is some kind of chemical that is used to treat soils.

- So, in areas immediately around homes, you can treat the areas with tea tree meal.

It's sold as a fertilizer, and so you can spray your planting beds with that tea tree meal, and it has saponins in it, which irritate the worms' skin, drive them to the surface, and when they're on the surface, you can pick them up by hand or scoop them up with a shovel if they're that thick.

- Okay.

- The problem is you can't treat an entire forested landscape with tea tree meal. - No, right, sure.

- It's not good for whole areas, but in smaller areas around individual homes, or individual buildings, that can be quite effective.

- Well, thank you very much for listening to this topic on Asian jumping worms.

I hope you learned something.

We don't want to alarm everybody, but it's something that everyone should be aware of, especially if he owned forest land property.