Mystery #3 (a) - Nightcrawler (Lumbricus terrestris) likely. - 3/30/12 - Sticks and Stones

2014-4-24 - Over a period of a couple of days I sent the following inf. to Sieglind and Sam:

University of Minnesota - recipe for a mustard solution that will bring worms up.

http://www.nrri.umn.edu/worms/research/methods_worms.html

They also say that you'll almost never find one by digging since they feel the vibrations and go deep down in the soil.

At this link, from the UK, there are pictures that more closely resemble your situation, sticks with gravel, and show and explain more closely what the piles look like in that case. Maybe there is some resemblance to yours:

http://mygarden.rhs.org.uk/blogs/miranda_hodgson/archive/2012/01/24/finding-earthworm-middens-in-the-courtyard.aspx

I also read that colonies increase by several feet a year, but I can't re-find the link.

Probably Lumbricus terrestris, aka Nightcrawler. Where other species of worms feed on things in the ground, the Nightcrawler is the only worm that comes to the surface to feed (on dead plant material).

A link somewhere said that the "sticks" are usually leaf petioles (stems). In the picture there do appear to be sticks small enough to be leaf stems, but there are several that are larger - some still have leaves attached. Since Nightcrawlers usually get to about 8 inches (and one was found in China at close to 20 inches!) it's conceivable that they can drag sticks the size in their picture.

Sieglind and Sam say this sure seems right to them. Yay! If it weren't for Charley Eiseman at BugGuide, I'd still be looking!

In the meantime, I'll equivocate on the ID. I'm sure eventually someone will see a Nightcrawler come up or a get a picture of one. Until then I'll be content to call it "likely".

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The below as posted to BugGuide 3/15/13
(the pic was deleted because it was thought not to be made by an insect. Charley Eiseman thought maybe it could be a worm/nightcrawlers.):

Sticks and Stones
near Danville, Illinois, USA
March 30, 2012

land-based larva of a net-spinning Caddisfly?

night-time Beetle or Beetle larva planting sticks?

something else?

Activity (building) seems to be happening at night
Activity is most apparent in the Spring

Beaver, otter, and the like, and birds, are highly unlikely.

I initially read about a land-based larva of Caddisfly, I think it was, but that seemed like a stretch. Then in Aug. last year I saw a picture posted on BugGuide that had some resemblance to this one and someone suggested Caddisfly, IIRC. I'm unable to find the picture again. After the picture was posted I renewed my effort to find a Caddisfly connection and couldn't find any more information.

Searching for some kind of larva, though, in September I found an abstract about a type of Ground Beetle larva luring amphibians in a predator/prey role reversal, but no mention of the larva using sticks or stones to beat a frog to death. (sigh)

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Following are the clues I've been able to tease out of the homeowners:

Sticks are being planted in the gravel paths of a lakeside home near Danville, Illinois. The sticks are "planted" in the soil between the gravel "not very deep". There are "many" clumps of these sticks. They say the soil is pushed up in little mounds into which the sticks are placed and that it puts them in mind of insect activity. They've lived in this home since the 1960's and they've only seen this happening in the last few years.

The owners estimate the sticks to be 2" to 3" long (6 to 7-1/2cm).

Winter 2011-2012 - This happened for most of the winter because, they believe, of the milder weather having kept the ground from freezing. On any given day they removed the sticks and then tamped down the area with a well-placed sole only to find the clumps of sticks reappear the following day. The activity was at its height in February or March, slowed somewhat in April, and, at last report, in mid-May that year, it stopped entirely.

Winter 2012-2013 - I suggested they ready their trowels and look for a larva. On Dec. 14th I got an eMail that the activity has begun again and that a carefully placed trowel and magnifying glass didn't produce results. I suggested they save up for a backhoe rental as I don't know how deep they need to dig for whatever is living there.

A thought, the lake wasn't always there, it was created in the 1960s, perhaps it took some years for certain types of insects (or whatever) to find the spot hospitable and for the population to expand to a certain size before their stick activity was noticed....?

Help me, oh, BG, you are my only hope.

I'll send the homeowners this link. Perhaps if they get some encouragement they'll be amenable to more digging.
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Contributed by K. Stutzman on 15 March, 2013 - 2:30pm

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info from Sam and Sieglind's eMails

4/14/12:
On our gravel paths across the road there are little clumps with little sticks sticking up. It is as if some little animal or insect is planting them.

Sam pulls out the sticks(which are not in very deep) and stamps the dirt down but there are quite a few and we wonder who or what is doing this???

5/9/12:
The activity seems to be slowing down. Seems to be mostly in the winter time. Wondered if their are some little bugs going around and planting sticks...doesn't make much sense especially since no bugs are around in the winter! We don't remember if it happens when the ground is frozen solid. The ground was soft most of the time this past winter due to unseasonably warm temperatures.

5/12/12:
The activity has stopped now.

5/21/12:
I better make myself a little more clear on these clumps. First of all they are not very big (tall) actually a little dirt spilled up from below with short (2 to 3 inches long) sticks sticking up. One can pull the short sticks and they are not attached and come right up. At this time, activity has long stopped. Seems to be mostly in winter. Almost as if a colony of little insects are below the ground and have a hole or home and push up some of the dirt and then something sticks these little sticks into it. Really odd.

We have experienced this for a few years now. Clumps would vary in places along the rock covered paths.

12/14/12:
Sure enough, they are at it again. We went out with trowel and Mag. glass but to no avail. Whoever or whatever, is keeping themselves hidden......STRANGE! We will still be checking every so often!

1/27/13:
The ground is still frozen but should thaw tomorrow or Tuesday (60 degrees forecast). Activity seems to be only on thawed ground.

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Fall of 2013 - I heard they got a special camera from one of their sons and they will set it up to see what they can find out.