Monthly Mystery #4: Little Nothings Stuck to Trees

That title could describe many of the things with which I concern myself, but what I have in mind here are some very specific little nothings.  In March 2011, Tom Murray posted this photo to BugGuide, wondering what was this ~3-mm perforated object he had found on a beech tree.  If I see an isolated little mystery thing like that, and especially if I don’t see it in person, I can just shrug it off without worrying too much about it, as I did in this case.  But then one day in October, I started seeing these things everywhere I looked.

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That day, they were all on young black birches, but I’ve since seen them on red maple and witch hazel saplings; I’m sure they’re placed indiscriminately, and just show up better on relatively smooth surfaces.  They are always oriented vertically, as in the photo above, but I’ll show some examples sideways since that works better with the WordPress format.

That first one is about 2 mm long and is fairly typical; there is always a row of holes on either side, and sometimes a central one at the bottom.  I’m not sure if the material is mud or excrement.  Here’s a side view of a particularly long one:

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The same one, viewed head-on:

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In this one, the holes apparently haven’t opened up yet:

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A few times, I’ve found one that instead of having empty holes, had these things where the holes would be:

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I can’t tell if they’re the remains of eggs or larval exuviae, but either way, I think it’s clear that these objects are egg cases.  I can’t think of anything other than a beetle that would cover its eggs with mud or excrement stuck to the side of a tree.  I have yet to find fresh examples, but I would bet they’re made in the spring.  A close-up of the last one:

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And one last variation:

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If I ever find fresh ones, of course, I’ll collect them to see what hatches out.

About Charley Eiseman

I am a freelance naturalist, endlessly fascinated by the interconnections of all the living and nonliving things around me. I am the lead author of Tracks & Sign of Insects and Other Invertebrates (Stackpole Books, 2010), and continue to collect photographs and information on this subject. These days I am especially drawn to galls, leaf mines, and other plant-insect interactions.
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7 Responses to Monthly Mystery #4: Little Nothings Stuck to Trees

  1. Interesting. I hope you find one. I have a couple of mysteries on my desk, too, hoping that stuff will emerge, and then to figure out whether it’s the primary builder or a parasite…

  2. Kinda reminds me of a mantis ootheca, though it’s obviously smaller.

  3. Sam Jaffe says:

    Hi Charley,
    We’ve been collecting a lot of red maple for feeding early season caterpillars at the lab and I am seeing your “little nothings” in abundance. Some seem unopened. As of today I am setting them aside when I come across them, I don’t suppose you have solved this mystery yet?
    – Sam Jaffe

  4. John van der Linden says:

    Hi Charley — John Pearson just emailed our Iowa-Insects list with a finding similar to these and shared a link to this post of yours. I have come across something similar, just once, in the spring, and placed it in a rearing container; as I recall a few tiny hatchlings emerged that appeared to be psocopterans, so I came to the conclusion it was the egg case of a bark louse. (Unfortunately the nymphs died and dessicated before I could get photos.)

    • Hi John–I referred John P. to this post after he showed me his photos (which are here)… Was your barklouse egg case like this one we found on MJ’s bluff?

      • John van der Linden says:

        Not really; it was more lumpy and three-dimensional, more like your first, fifth, and six photos in this post, and if I remember right there were holes in it too like what’s shown here. I’ll try and get it posted to BG. Interestingly, at the time I collected it, there was an extremely small, elongate orange and black insect with six legs that was actively moving over the object and in and out of its nooks and crannies, as if it were hunting…I got some OK photos.

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