Two remarkable cases of mimicry

Both of these cases were found by Matthew Cobb on Twi**er, and I’ve enlarged the photos at the bottom:

and

I think I’ve shown the buff-tip mothsh (Phalera bucephala) before; they are remarkable mimics of broken sticks when at rest. Now we’re not absolutely sure if this form of camouflage, presumably protecting the moths from predators, was the evolutionary impetus behind their appearance, but it seems likely, and could be tested in the lab with bird predators. I can’t think of any other explanation.

Here’s the adult with wings spread a bit (from Wikipedia):

Here’s the photo above, enlarged, clearly placed among broken sticks to show the mimicry:

Here’s another photo; note that the head is small, like the tip of a twig, and the legs are inconspicuously pressed down on the substrate. And of course its color and pattern are just like a broken twig:

Here’s the leaf katydid enlarged (the group is named in the tw**t above). It’s almost impossible for us to spot this: it even has a “rotten spot” mimicking those of leaves, as well as a yellowish body outline and a behavior that makes it place its front legs directly forward, looking like a leaf stem.  None of this would have evolved had the color, pattern, and behavior not given those individuals a selective advantage over less perfect mimics. This says something about the visual acuity of the predators and the power of natural selection.

I don’t know Latin, but I think the genus name, Phyllomimus, means “leaf mimic”.

 

15 Comments

  1. GBJames
    Posted May 30, 2017 at 9:05 am | Permalink

    wow

  2. rickflick
    Posted May 30, 2017 at 9:47 am | Permalink

    These critters give me shivers. They are totally almost too strange to be true. If you didn’t have any idea of natural selection, as in everybody before Darwin and a some even after, you’d have to be religious.

  3. Gregory Kusnick
    Posted May 30, 2017 at 11:00 am | Permalink

    It’s interesting that the katydid positions its “stem” end at a place where leaf stems don’t normally sprout — and gets away with it. This too says something about the observational powers of the predators.

    • W.Benson
      Posted May 30, 2017 at 1:14 pm | Permalink

      I suspect the katydid would be considerably harder to see if photographed for one of Jerry’s find the animal contests.

    • Diane G.
      Posted May 31, 2017 at 3:00 am | Permalink

      In the same way that some animals have eyespots on their posterior bodies/appendages, to attract attacks away from the generally more vitally important anterior regions, perhaps having the head-end most resemble the stem serves the same purpose.

  4. Posted May 30, 2017 at 11:53 am | Permalink

    Spectacular mimics. The faux fungal leaf spot on the katydid is a nice touch. Makes me want to reach for the sulfur spray.

    I love mimicry because it confirms the process of evolution so well. Why would God want to make a moth that looks just like a twig?

    • GBJames
      Posted May 30, 2017 at 12:03 pm | Permalink

      To test your faith! He’s such a trickster.

  5. Mark R.
    Posted May 30, 2017 at 12:40 pm | Permalink

    That katydid’s “dead spot” even shows leaf veins. Truly remarkable!

  6. Posted May 30, 2017 at 2:35 pm | Permalink

    I know there is at times a distinction to be made between the terms mimicry and camouflague. That is, mimicry is where one resembles a specific object. Camouflague is where one blends into the background. Here the terms are used interchangeably. I find that this is agreeable here, since these insects are doing both in a way.

    • Posted May 30, 2017 at 5:21 pm | Permalink

      Is it fair to say mimicry is a particular type of camouflage? Camouflage can take other forms, such as dazzle camouflage.

      • Posted May 30, 2017 at 6:56 pm | Permalink

        I suppose in a philosophical sense a mimic such as a jumping spider that resembles an ant is also ‘doing’ camouflage. It seems that the two terms are so close that it is a bit of a muddle.

      • Gregory Kusnick
        Posted May 30, 2017 at 7:03 pm | Permalink

        I wouldn’t say so. Camouflage implies a desire to escape notice, whereas Batesian mimicry is meant to catch a predator’s attention and warn it off.

        • Posted May 30, 2017 at 7:17 pm | Permalink

          Yes, you are right.

        • Posted May 30, 2017 at 7:25 pm | Permalink

          Mimicry is looking like something else and camouflage is avoiding detection. Mimicry might be for the purpose of camouflage and camouflage might utilize mimicry, but they are distinct concepts.

  7. Posted May 30, 2017 at 6:35 pm | Permalink

    As kirmit sings “it’s not easy being green” sometimes it is a necessity, although when a leaf starts staring back at you…
    this post coupled with the one of the juno probe passing Jupiter (amazing footage) makes one feel a little weird, in a awe struck way… creatures looking like pieces of broken branch.
    It makes you wonder what the hell could be out there.


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