Sunday morning mimicry

July 16, 2017 • 8:45 am

I needn’t explain why I’m so fascinated with the phenomenon of animal and plant mimicry, so let us just marvel at two examples this Sunday morning as we worship at the church of Our Lady of Perpetual Naturalism.

Both were found by Matthew Cobb, and both were retweeted by Gil Wizen from the same source, which is written in Japanese. The first is a leaf-mimicking moth. Can you spot which one is the moth?

The species is found in China and Taiwan, and looks like this when pinned. Look at the markings of the forewings:

Here’s a video showing the stunning mimicry; its wings are not curled but give the illusion of it. It’s remarkable!

And a behavioral adaptation to facilitate hiding. Several insects repeatedly turn around when moving, like this one. Can you guess why? Put your guesses below, and then see the answer here.

 

xxx

Another clue: here’s the image of one species in the genus. Its head is to the right.

15 thoughts on “Sunday morning mimicry”

  1. It walks backwards ,because it is better to lose your tail than your head.
    That Chinese moth is amazing .

    1. Yes, and also It’s a bit like leading the target in trap shooting, aiming for where the target will be rather than where it is, only in this case, the predator aims for the “head” only to have the insect leap or fly off in the opposite direction. I just read about this insect in a little (and slightly dated) book “Mimicry in Plants and Animals”, by Wolfgang Wickler. Fascinating stuff!

      1. I think I have that book from 1968 in a box somewhere. I’ve always thought of it as a little gem.

  2. My mind is blowing right now. I know about the leaf curl mimic, but the weevil mimic is new to me.
    On the leaf curl mimic, there are little separate details that wonderfully work together to ‘sell’ the deception.
    An artist painting a curled leaf on a flat canvas would spend a lot of time doing the same with pigments, and they could not do it better.

    1. Same here, in the tweet pic. I keep trying, but I can’t do it. I go back to the pinned oic to get my eye in, but it doesn’t help!

  4. Both great examples of mimicry. The backward walking certainly fools the eye into thinking the rear end is the front end. It also creates a confusion as too what species we are looking at. This could reduce the chance of predation.

  5. In this brief clip, we see the hemipteran walking backward, in weevil mode, only on the top side of the stem, when it’s visible from above. On the underside, it turns around and walks forward.

    1. We don’t have video of the leaf-curl moth, but I conjecture that it too has a strategy of turning to keep its trompe-l’oeil face-on to potential predators.

  6. Not sure why an edible insect would increase its fitness by pretending to be a weevil, which is another edible insect, far as I know. But to deveive about which is the head end makes good sense.

  7. What is the basis of the weevil mimicry? It seems unlikely that weevil’s are toxic or evil-tasting. Eurybrachid planthoppers are reported to jump to escape predators and are for the most part seem camouflaged to live on bark and twigs. Although many Hemiptera produce repulsive secretions, this does not seem to be the case with planthoppers.
    Eurybrachid bugs are soft-bodied and relatively large (adults abt. 7-25 mm long), a good sized morsel. Predators such as birds and lizards may learn to ignore weevils because of their hard, abrasive exoskeletons (difficult to crack open and indigestible) and their slipperiness, which may help them escape. If weevils are unworthy as food, this might help mimetic Ancyra avoid predation.
    Other naturalists have stressed a possible role of “auto-mimicry”, where the head of the insects mimics the tail-end, thus prompting predators to attack the ‘wrong’ end of the prey and allowing the animal to escape by jumping or flying in an unexpected direction. Neither of these two possibilities excludes the other.

    1. As to why mimic a weevil, perhaps it is a matter of evolving in that direction because of its starting point. Suppose the rear ends of its ancestors by chance kind of vaguely resembled the head end of weevils. Natural selection would then continue to refine that. It could have just as well started as being the head end of a different kind of planthopper, or a true bug, or whatever.

    1. That is a beautiful insect. Not sure if it is mimicking a moth, but rather mimicking something else (like a transparent, skeletonized leaf? A flat windborne seed?). And by symmetry it happens to look moth-ish.

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