Black caterpillar with yellow-orange stripes

2012 April 28

When Sam caught this one in the yard on June 13, 2010, I thought it was going to be an easy ID. Pretty good-sized caterpillar, distinctive-looking striping; should be a piece of cake, right?

But, it turns out to be not so easy. I went all through Caterpillars of Eastern North America, searched BugGuide, posted it on BugGuide for ID, did Google searches on variations of “black caterpillar yellow orange stripes”, and even tried dropping the actual picture into the Google Reverse Image Search to find “similar” photographs[1]. Nothing. The pictures have been sitting on BugGuide since early October 2011, and nobody has even made so much as a guess yet, so it’s obviously a lot harder than I thought.

The closest I was able to find weren’t all that close: the Orange Striped Oakworm has about the right coloration, but is way too big, not hairy enough, and has a bunch of fleshy protuberances on its back. Some of the caterpillars of the moth genus Datana are hairy enough and similarly-striped, but they have much more colorful heads and necks and have a characteristic way of arching their backs that this one didn’t do.

Unfortunately, I didn’t get all that many good pictures, because Sam was playing with it at the time, and neither the little girl nor the caterpillar were too keen on holding still for me. In retrospect, I should have tried raising it up to adulthood to see what it turned into. Oh well, too late now. Maybe one of these days, we will find another one and be able to try again.

In the meantime, does anyone recognize it?

[1] The google reverse image search is a neat idea[2], but in this case it was more amusing than helpful. For one thing, the pictures “similar” to my caterpillar turned out to be mostly of women’s eyelashes, like this:

Now really, Google. Is that a nice thing to say about their eyelashes? They probably wouldn’t appreciate being considered “similar” to that fish head, either.

[2] In most browsers you can open two browser windows, with google image search open in one of them, and just drag and drop images from the other window into the search box. Google will then try to find not just exact copies of the image, but also images that are similar according to whatever arcane criteria the Google engineers have cooked up. I first heard about Google’s “reverse image search” when Alex Wild posted about it in June. Where it is really useful, is in finding out whether other sites are using one’s pictures. This is really important for people like Alex, who are professionals and want to make sure that their pictures aren’t being used without payment, but even for a hobbyist like me it is amusing to see which of my photos get picked up and circulated around the Internet. Some of my hottest pictures for being copied appear to be the pseudoscorpion (57 hits):

and the male wood tick (130 hits):

9 Responses leave one →
  1. April 28, 2012

    I think it looks like this.

    Google reverse image is way cool! Thanks for the tip.

  2. April 29, 2012

    looks like a really beat up forest tent caterpillar (or something closely related). i recognize the butt, i have a similar pic:

  3. April 30, 2012

    KT: I’m surprised that one didn’t come up on the image search too.

    Hadel: You’re right, it does have some similarities to the Forest Tent Caterpillar, which we certainly do have around here. The orange stripes are spot-on, as are the underbelly hairs. It would just need to lose the back hairs and the white spots running down its back, and change its primary body color from powder-blue to black. Hm. I wonder if it was infected with the same species of Pseudomonas bacteria that turns some of our local monarch caterpillars black before it kills them? If that’s the case, that would certainly explain why nobody has been able to ID it.

  4. May 28, 2012

    i found one 2! were goin 2 raise it 2 see what it turns out like. i can keep u updated

  5. May 28, 2012

    oh ya and it was found in durango colorado?

  6. May 29, 2012

    Sophie: Great! I hope it matures OK so we can find out what it is. I’ll try looking for more specimens up here (they should be around in the next few weeks), but one never knows how things like that will work out.

  7. Melanie permalink
    June 16, 2012


    We get these darn catarpillars every year. I just found your site because in stead of eradicating them this year I thought we’d wait and see what they turn into. Unforunately, they have already wipes out 1/3 of my privet hedge so they will have to go. I could keep a couple in a terrarium if you are interested.
    I have about 500 right now, they are everywhere here. We live in CentralEast Ontario and they love this cool weather with warm sun in the day.
    Let me know if you would like us to keep a couple. They are interestingly friendly and will stare up at you when you start talking to the jar. Try it.
    They are NOT forest tent’s – we don’t have many of those here.
    Just another thought – I work for the federal gov of agriculture. I could defintely take these to the bug farm and get an ID!

  8. June 17, 2012

    Melanie: Yes, please! If you could raise up a few in a terrarium, that would be great! And if you could get them IDed by your Dept. of Agriculture, that would be great, too! So far, we haven’t found any more around here, and I’d really like to know what they are.

  9. Trav permalink
    June 5, 2014

    I have found one haven’t seen this kind for a long time around here 10- 15 years around Westminster Co

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