Asian Jumping Worms

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JHarkness
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Asian Jumping Worms

Post by JHarkness » Tue Aug 14, 2018 4:34 pm

ENTS,

Asian jumping worms recently spread their way up along the Hudson River, but this spring they were reported in Hillsdale, New York, just a short drive from my forest. I knew it would happen when I heard the news, and sure enough, today it did. I was exploring a part of my forest I don't often visit, the purpose was to inspect and photograph a recently deceased beech tree for an article I'm writing on BBD. The good news is that the beech is amazingly still alive and actually seems to be getting better, in fact all of the beeches here are alive and well, the scale insect can't be found on any of them and none have the neonectria fungus. While inspecting the largest beech, I heard a noise at my feet, I looked down and see what appeared to be a small garter snake slithering away downhill, I ignored it and go back to work, then I heard another, followed by several more. It turns out that they were Asian jumping worms, they're fast, hard to catch and massive no less, none of the European species I'd seen before come anywhere close to it's size (the largest I found was just shy of 10 inches in length, most were between 6 and 8 inches, however). The leaf litter is dwindling at this site now and the soil is almost nothing but earthworm castings, curiously, a lot of fine roots remain with no obvious signs of damage. The most disturbing part of this is that I surveyed the same site in May before leaf out and found no evidence of earthworms of any kind. The soil is so bad here that I almost uprooted a 3-inch diameter healthy beech by grabbing onto it for support. There are absolutely no seedlings here now, there were in the spring but it appears they've been washed away thanks to the worms.

I rushed back home and made up some mustard solution (mustard powder mixed with water), though I don't know why I thought I needed it, the worms were literally coming out of the forest floor by the dozen and the mustard solution failed to bring any more out. Anyway, I ended up returning home with a container of roughly 50 earthworms (I couldn't count them at all thanks to their near constant thrashing, from which they get their name). I realized that I had recently seen damage from them in another part of my forest (recently reforested agricultural land this time) without realizing what did it, I made my way there to collect no less 80 of them in a just a few square feet, I made, in now way, a dent in their population at this site. Again, this is a new infestation, it was not here last fall. The latter site has absolutely no leaf litter or duff layer, just worm castings, the soil is still rich organic soil though, but who knows for how long, it's already rapidly washing away.

My question is, is there any research being done on these worms and possible ways to control/remove them? I had read that increasing nitrogen in the soil will kill earthworms off, I experimented with this and found it actually dramatically increased the density of earthworms (these were European species, however). Presently, I'm just visiting the most affected areas and removing as many worms as I can by hand or with mustard solution, it's effective at controlling European species (assuming you know where they are) but I have no idea if I will be able to keep up with the jumping worms.

The thought of European earthworms invading the area was bad enough, but this is on a whole other scale, I've never seen damage like this before.
"Be not simply good; be good for something." Henry David Thoreau

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RayA
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Re: Asian Jumping Worms

Post by RayA » Tue Aug 14, 2018 6:42 pm

Joshua,

This was just sent to me by my friend Bill... it might interest you:

https://vtinvasives.org/news-events/eve ... ake-wormso

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JHarkness
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Re: Asian Jumping Worms

Post by JHarkness » Tue Aug 14, 2018 8:20 pm

Ray,

Thank you for the link. It looks like a very interesting event and I'd enjoy attending, I don't know if I have the time for it, but we'll see.

I'm very impressed with Vermont's attention to invasive species, NY still ignores my attempts to report European nightcrawlers in the area because they "don't recognize the species"...

Joshua
"Be not simply good; be good for something." Henry David Thoreau

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Erik Danielsen
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Re: Asian Jumping Worms

Post by Erik Danielsen » Wed Aug 15, 2018 5:52 am

Josh,

That is extremely concerning. I hadn't heard about this species until earlier this year, but it sounds like it has the potential to do a lot of damage. The change in soil texture is concurrent with the obliteration of most of the fubgal community's fine hyphae in the soil, which can disrupt their symbiotic relationships with the plants, especially trees.

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JHarkness
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Re: Asian Jumping Worms

Post by JHarkness » Wed Aug 15, 2018 7:49 am

Erik,

Yes this is very concerning, however there's a bit of good news with it, unlike the european species which eat the organic soil just below the duff layer including the fine roots of trees and fungal mycelium and then later eat the upper portions of the duff layer and the most recent leaf litter, these worms seem to prefer the most recent leaves and start feeding there. I noticed that leaf litter shrunk rapidly and the organic soil in one site had become extremely aerated and was largely made up of worm castings, but there were still quite a lot of fine roots and mycelium, they are eating them, but not to the extant that the european species do immediately. Even in the most severe infestation on my property, there were surprisingly a lot of fine roots, very little mycelium, but there was stil some. Hopefully this means that people will be able to spot and deal with the problem before it get's too severe.

Joshua
"Be not simply good; be good for something." Henry David Thoreau

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JHarkness
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Re: Asian Jumping Worms

Post by JHarkness » Wed Aug 15, 2018 8:18 am

Erik,

I just checked the DEC's iMapInvasives site and disturbingly, there have been much more widespread reports of jumping worms than I thought, they have been reported in Westchester, Sullivan, Ulster, Dutchess, Columbia, Rensselaer, Saratoga, Warren, Madison, Cortland, Tompkins, Chemung, Rochester and Ontario counties. They have not yet been reported in the Housatonic River watershed (where I am), but I'm sure they are in other places in the watershed.


Joshua
"Be not simply good; be good for something." Henry David Thoreau

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dbhguru
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Re: Asian Jumping Worms

Post by dbhguru » Wed Aug 15, 2018 5:30 pm

Joshua,

Awful news. #%^*#}{ worms. However, I can imagine some of my relatives who fish jumping for joy. Tham suckers jump right up onto your hook. Wheee doggie!

Bob
Robert T. Leverett
Co-founder, Native Native Tree Society
Co-founder and President
Friends of Mohawk Trail State Forest
Co-founder, National Cadre

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JHarkness
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Re: Asian Jumping Worms

Post by JHarkness » Wed Aug 15, 2018 11:45 pm

Bob,

Oh yes, I believe I have a few relatives who would go crazy over these worms as well...

As of tonight, I have removed a little over 400 Asian jumping worms from several spots on my property, I believe I've found the extent of the infestation and the good news is that it's nowhere near the old growth remnants in the woodlot or the individual old growth trees in the mature second growth forest (where the ash and tall birches are). However, protecting this area is very important as it has one of the last stands of hobblebush on the property and, surprisingly, a stand of spicebush, it turns out there once was a stream here but it has vanished with the undergrowth.

One strange thing I've noticed is that they seem to displace the European worms, has any one else seen this? Another strange thing I've observed is that they appear to be migratory, a large hatch occurred at the top of a ridge on my property and the now mature worms are traveling downhill, completely in control. Farther downhill I found an area where they've been for at least two years, it would be interesting to save a small handful of them and see if they manage to make their way back up the ridge, but I won't be letting them do that.... The only way so many of them could have ended up at the top of the ridge is if a large number made it there last year. I've barely made a dent so far, but I'm making progress and I won't be stopping until I can't find any more. I would imagine that if I can get a handle on the deer situation, song birds, turkeys and grouse would be able to return and eat the worms, this spring I noticed robins and bluebirds hunting European worms in the forest, but they wouldn't go anywhere where deer browse was heavy.

Oh, and guess where the highest worm densities were? Around invasive burningbush, barberry and corktrees, surprise....

I will continue to post updates on the removal work.

Joshua
"Be not simply good; be good for something." Henry David Thoreau

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JHarkness
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Re: Asian Jumping Worms

Post by JHarkness » Sat Aug 18, 2018 10:46 am

ENTS,

Unfortunately, the infestation is much, much worse than I feared, it now covers almost twenty acres on my property, some of the areas where I've seen European earthworms before now have jumping worms as well. But there is a bit of good news, I've found high densities of them on one site on my property which is has had an increase in thickness of the leaf litter and duff layer, and an increase in the amount of green growth. I also identified a site with absolutely no earthworms and a healthy duff layer, but absolutely no green growth. What's going on here? Deer, unsurprisingly... there is no deer browse where there's an increasing amount of green growth (including some rare species that are highly affected by worms, such as painted trillium), and there's heavy deer browse where there are no worms. The areas that are suffering the most from worms also happen to be where deer densities are highest. I'm thinking that there's a relation in the amount and vigor of herbaceous vegetation and earthworms, essentially, I'm thinking that the worms (at least for now) are leaving plant roots alone and these plants are able to connect with the weakened fungal networks and gain enough nutrients. Also of interest is that the recovering site had almost no green growth just five years ago and hardly had any ferns, now the ferns are thriving, I've even seen an increase in them just this summer.

I plan to start a scientific study of this this summer and fall, I would be very pleased if any of you could check for worms in areas with high deer densities and in areas with low densities and see how that relates to the herbaceous plant community (specifically species that are usually highly affected by worms).

I will post updates on the BBS as the study progresses. I'm also planning to get in touch with researches at Cary Institute who are studying earthworms and see what their thoughts on the matter are.

Joshua
"Be not simply good; be good for something." Henry David Thoreau

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JHarkness
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Re: Asian Jumping Worms

Post by JHarkness » Sat Aug 25, 2018 8:26 pm

ENTS,

I recently returned from the presentation on jumping worms in Woodstock, Vermont. I won't write much tonight, especially as I want to test some theories on the worms here. Anyway, the information I received today was quite contradictory to what I had heard of the jumping worms before, apparently, they do not compact soil like nightcrawlers do, nor do they deplete the duff layer as fast as they don't take leaves into their burrows to eat later. Apparently, in a healthy forest the jumping worms don't cause much damage, most species affected by nightcrawlers survive. I was shown a number of sites on their property and was amazed out the amount of wood ferns, cinnamon ferns, Christmas and rock polypody ferns in addition to red trillium, trout lily, soloman's seal, American ginseng and more that were surviving, and seemed to be thriving, the top layer of leaves and duff was full of mycelium and mushrooms, beneath it however, are worm castings, far worse than any that I have on my property. The University of Vermont has actually studied a direct association between the worms and white-tailed deer. Apparently, on their own, the worms aren't enough to decimate a forest floor, it's mycorrhizae or the undergrowth, it's been found that the worms will cause a decline of some of the most susceptible species, coincidentally favorites of deer, causing the deer to change their browsing habits to other herbaceous plants and woody plants, eventually the understory is destroyed by deer leaving worms with optimal conditions for survival, therefore, their population explodes and the duff quickly disappears. The good news? There are ways to stop them, or keep their numbers manageable.

I will write more tomorrow, overall this was an excellent workshop.


Ray, thank you for letting me know about this, I feel the work National Forest and the University of Vermont are doing is a huge step in the right direction, oh and they have the nicest managed forest I have ever seen. Much of it's less than 150-years old but the whole thing has old growth characteristics thanks to their careful management.

Joshua Harkness
"Be not simply good; be good for something." Henry David Thoreau

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