A beetle that mimics a wasp

January 4, 2017 • 1:30 pm

I’m working simultaneously on a talk and a children’s book (talk about brain-stretching!), and I have no neurons to spare today. So, courtesy of ever-attentive Twi**er watcher Matthew Cobb, have a look at this wasp-mimicking beetle.

Entomologists have weighed in, tentatively identifying it as a Cerambycid (longhorn beetle), probably in the genus Enchoptera.  It looks to me a bit like the wasp mimic E. apicalis, but the coloration isn’t right.

The wasp it’s mimicking is probably a gasteruptiid wasp; and here is your quiz:

a. If it is a mimic of such a wasp, and the beetle is itself edible and not toxic, what kind of mimicry is this called? You should know the answer by now.

b. If it does mimic a gasteruptiid, one would expect to find the “model” wasp in the same area. After all, a predator’s avoidance of this species, if it is a mimic, would probably have to be learned by, say, a bird who has encountered the wasp, forms an image of it (to avoid it), and then applies that image to the beetle, giving it a selective advantage. (Such avoidance could of course be evolved.) Can you find the Australian model? I’ll leave that to you, but do note that the mimicry hypothesis does make predictions.

18 thoughts on “A beetle that mimics a wasp”

      1. A piece of advice I picked up from someone long ago and used to great advantage while buying books for my –and other’s– children. (I don’t mean to lecture you PCC(E)m but you don’t have kids and you may have never heard this.)

        Kids like to read about kids who are about two years older than they are. If your target audience is 8 year olds, a 10 year old protagonist works.

        It astonished me how accurate this was with my kids.

        1. That idea matches my intuition. The reason it may be that kids look up to the older kids is that it provides a heads-up into their future, which must seem quite challenging. To a growing child, the older generation must seem the closest thing to prophets. A defense against being caught by surprise.

  4. Tricky thing about mimicry, the model and mimic may currently be sympatric or at may have been historically sympatric but are not currently. The model could be extinct for reasons other than predation and the mimic lingers on. Or, the predator applying pressure may have a range that includes both model and mimic even though the model and mimic are not sympatric. Imagine a migratory bird with similar feeding habits on both sides of a barrier to insects that keeps them allopatric and yet they converge on the wasp form.

    1. The original poster’s query about mecoptera wasn’t badly informed — a nonspecialist photographer [or bird?] would easily overlook the epaulet-like elytra. The only common Australian Mecoptera are hangingflies [Bittacidae] in the genus Harpobittacus, and to my eyes the latter have more than a passing resemblance both to Encoptera and to the wasps mentioned as models above. I’ve never been to Australia and don’t know if all of these overlap in habitat and season, but wouldn’t be surprised if the hangingflies were also memmbers a quite elaborate ring of Batesian and Mullerian mimicry using this model.

      1. Others have noted the resemblance as well. Having a look around in the Atlas of Living Australia I’m going to take a stab that the beetle is Tribe Macronini to which the genus Echoptera belongs but is instead genus Macrones. In Sydney the range would overlap with hanging flies

    1. Of course that could also be a mimic (a Müllerian mimic) of our mystery Gasteruptiid. :/

    2. Yeah I would have guessed an Ichneumonidae as a better match. The Gasteruptiidae I’ve seen are very weird looking.

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