Flower mimicry FTW

February 12, 2014 • 4:09 pm

We simply must have some mimicry for Darwin Day, for mimetic animals provided some of the earliest evidence for natural selection.

This picture, by the ace photographer Igor Siwanowicz, is of a flower-mimicking mantid.  The hornswaggled pollinators get eaten, of course.

Can you spot the mantid? 🙂


From Twitter via Matthew Cobb ~

29 thoughts on “Flower mimicry FTW

  1. I believe you meant to write “hornswoggled” (with an “o”). But thank you anyway for using this great word, which I don’t think I’ve seen in use since 1829.

  2. For years and years and years, in biker and punk rock and tattooist circles, ‘FTW’ has been an acronym meaning ‘F*ck The World’.

    So it’s confusing to see it in your post titles, until I remember how the young ‘uns use it these days!

  3. I guess pollinators are not fashionistas? If they were, they would caress with great delight the luscious, velvety softness of the true flower on the right while turning up their attennae at that crinkly, crepe-paper, scratchy thing on the left. 🙂

  4. Yay! Igor is one of my all time favourite photographers.

    And it is only fair that insects should mimic orchids. After all, orchids have been making a living from mimicking insects for yonks*.

    *Pairs with “hornswoggled”, both of them among my Father’s favourite words.

  5. It can’t be good for the plant to have mantises nomming its pollinators. There should be anti-mimicry adaptation, unless the mantisses play a role in pollination.

    1. I am not sure that this follows. The mantis will only catch a proportion of the pollinator insect population, leaving plenty of others alive to go about their pollinating business. As long as the orchid gets pollinated it doesn’t ‘care’ how many insects got killed by flower impersonators. If anything, the effect of the mantis would be to create a selection pressure on pollinators to better discriminate between real flowers and disguised predators.

      1. I disagree. Plant fitness is sometimes measured in the number of different pollinators it successfully attracts (see some of Ian Baldwin’s paper from the MPICE). That is one explanation for why wild tobacco flower nectar contains nicotine. The sugars draw in pollinators but the nicotine turns them off and keeps them from sitting there all day slurping it down without sharing. This way, a larger number of pollinators visit the same flower for a sip (but not a slurp) of nectar. The overall effect is that that flower’s pollen will be carried to a larger number of female flowers (and its female parts receive pollen from a larger number of distinct individuals).

        If there is a mimic insect eating a plant’s potential pollination partners, that should be mostly bad for the plant, unless it also eats herbivorous insects which might harm the plant (mantids usually want something bigger I suspect). This could be considered a form of parasitism. Cryptoparasitism perhaps? I am curious to know others’ opinions here…

        1. Mike, I agree that if the mantis significantly reduces the numbers of pollinators reaching the flower then that would be harmful to the plant if it meant that its pollination success was reduced. However, my thoughts were based on the view that, generally, predators are substantially less numerous than their prey and if a small proportion of prey individuals are killed that still leaves plenty more to come in and do the pollinating (this would be even more the case if several pollinator species are involved). Of course, if local conditions allow the predator to seriously depress the prey population then that might have an effect of the kind you suggest.
          I would also suggest that the mantis is likely to be just one source of mortality for the pollinators and not necessarily the most significant so any adaptations the plant might develop to counter the mantis harvesting its pollinators might be negated by other sources of pollinator mortality such as predation by other species like spiders, birds etc.
          Finally, it is perhaps also worth saying that if it is true that predation by the mantis affects the plant’s fitness then the selection pressure on the pollinator insect to discriminate better between real and deceitful flowers would also be beneficial to the plant.

          I am of course speculating and like Mike in Barcelona would be very interested to hear the views of others.

        2. Interesting thoughts. It’s hard to imagine how a plant could adapt to such an opportunistic insect hunting strategy (and it’s such a beautiful mantis anyway). One way that occurs to me relates to the release of plant volatiles to attract beneficial insects, such as parasitoid wasps which prey on herbivorous insects based on plant volatile cues. This can even occur in the soil in response to root feeding, as in the case of the Diabrotica-Heterorhabditis system. But the present case is sort of the opposite: an uninvited predator dispatching beneficial insects based on a resemblance to the flower. In this case, (if the impact were significant) the plant would have to slowly evolve volatile production which either repelled the mantis or attracted something which preyed on the mantis. What eats a mantis?

          Of course, if mantis predation on pollintors really were exhaustive, then those flowers wouldn’t reproduce, leading to die off or emergence of different looking flowers and the mantis would have spent millions of years evolving a mimicry strategy for nothing. There is something to be said for keeping your cash cow alive.

  6. As an orchid specialist I am highly sceptical about the ‘orchid mimicry’ hypothesis. Sure, these insects do resemble certain orchids, but is this more than the result of convergent evolution? I would like to know if these mantis species actually co-occur with any orchid species that they (somewhat) resemble. I doubt this.

    I often see images of these mantises where they sit on the flowers of man-made orchid hybrids, which gives away the manipulating hand of the photographer.

    I have also seen photos of these mantises catching dragonflies, which are not orchid pollinators, or blow flies and butterflies, which do not pollinate Phalaenopsis (the orchid in the photo here, which is a hybrid too). It therefore seems unlikely that they especially prey on orchid pollinators. This suggests that there is no specific mimicry of orchids involved.

    It is more likely, I think, that these insects just mimic some generalized zygomorphic flower, either to attract foraging insects or in order to look ‘harmless’, which allows them to ambush various small animals.

    1. I’d always assumed flower mantids were ambush predators, and that the colouration and form were to hide them from both their prey, and their own predators. Against this is that they sway and move about a fair bit. I used to watch orchid mantids (Hymenopus coronatus), a rare visitor on our frangipanis, back when growing up in Malaya. When they were about they were easy to find because of how they moved.

      It turns out I was wrong, and recent experiment shows that they really are aggressive mimics: http://www.jstor.org/stable/10.1086/673858 — Pollinator Deception in the Orchid Mantis, James C. O’Hanlon, Gregory I. Holwell, and Marie E. Herberstein

      We found that, as predicted for mimicry, the color of H. coronatus is indistinguishable from the color of sympatric flowers for hymenopteran pollinators. Field experiments show that isolated mantises attract wild pollinators at a rate even higher than flowers and capture these pollinators as prey items.

      I wonder if a similar result would be found for other flower mantids?

      1. This paper shows that the mantis species studied does not mimic any particular kind of flower, let alone an orchid. Rather, it offers visual cues that are highly attractive to hymenopterans, apparently its main prey. This confirms what I wrote above.

        1. Really? I thought you wrote that you were “highly sceptical about the ‘orchid mimicry’ hypothesis”. Is your alternative hypothesis that hymenopterans have evolved to be attracted to mantids in general? That’d be a tough sell.
          Perhaps you should have stated precisely what you thought “the ‘orchid mimicry’ hypothesis” entailed. Without that, you’re pulling a bait-and-switch.

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