Incognito Insects: camouFLYged

Most forms of disguise provide protection against predators, called Batesian mimicry.  In the fly world, flies often mimic bees and wasps (Family: Hymenoptera) probably because of their defensive sting.  The most common example of this are the hover flies (Family: Syrphidae). The hover flies are such good mimics that they easily fool most humans (Golding 2005). This includes even the most keen incoming Insect Ecology undergraduate students… at least for the first couple times!  Hover flies are such good mimics they even seem to buzz with confidence.  (Although, Rashed et al (2009) proved that their buzz does not acoustically resemble the hymenopterans they are mimicking.)

Here are some examples of hover flies mimicking bees:

hoverfly2

Hover Fly (Family: Syrphidae), Photo: Sean McCann

and

hoverfly

Hover Fly (Family: Syrphidae), Photo: Sean McCann

As you can see from the pictures above it is popular for flies to mimic bees. There are, believe it or not a few cases where insects will mimic flies!  This mimicry goes against rationale because flies, for the most part, do not have any defence against predators like the bee’s sting.  

Here are some examples of insects camouFLYged:   

This is a moth species found in Asia that mimics two flies eating feces!  There is little information on this flying mural but Allan Lee reported in 2009 that the moth reinforces the imagery with a pungent odour.

5184337925_0c36c26e21_o

Macrocilix Maia (Order: Lepidoptera), Photo: Bettaman

A new species of weevil found in Brazil appears to mimic a Flesh fly (Family Sarcophagidae).  This weevil has red “eye” spots on the pronotum and grey and black strips on its pronotum and elytra making it appear very similar to the Flesh fly.  While this particular species is a new discovery, there are other models within the subfamily Conoderinae that model house flies (Family: Muscidae), tachinid Flies (Family: Tachinidae), and horse flies (Family: Tabanidae).

beetle mimicing fly

Timorus sarcophagoides (Order: Coleoptera), Photo: Tadeu Guerra

and finally, a Treehopper found in Australia that mimics a fly . This Treehopper also has red eyes and a striped thorax similar to Muscomorpha.

Treehopper

Cephaloconus tenebrosus (Order: Hemiptera), Photo: Attila Monostori

So why would these insects want to be a fly?  All three examples are from warm regions where there is a lot of insects and a variety of insects.  I would guess that these fly mimics are monopolizing on two aspects 1)  the well-known speed and agility of flies to escape predators and 2) the sheer number of alternative meals.  (It’s an insect buffet out there!)  These mimics are hoping that predators will take one look at them and decide to pursue an easier meal.  Another hypothesis  is that the fly that they are mimicking simply tastes bad to predators.  Although I haven’t heard or read any testimonials regarding the latter hypothesis.  

Citations:

Bettamen (2013). Macrocilix Maia. [Photograph]. Retrieved February 6, 2014 from http://www.juxtapost.com/site/permlink/7e70b330-3b9e-11e2-88a1-233c342abfb0/post/macrocilix_maia/

Golding, Y., Ennos, R., Sullivan, M., and Edmunds, M. (2005) Hoverfly mimicry deceives humans. Journal of Zoology, 266(4) 395-399.

Guerra, T. Timorus sarcophagoides [Photograph]. Retrieved February 8, 2014 from http://www.biodiversityinfocus.com/blog/2012/08/09/new-species-wants-you-to-see-no-weevil/

Rashed, A., Kahn, M. I., Dawson, J.W., Yack, J.E., and Sheratt, T.N. (2009) Do hoverflies (Diptera: Syrphidae) sound like the Hymenoptera they morphologically resemble? Behavioral Ecology, 20(2) 396-402.

One thought on “Incognito Insects: camouFLYged

  1. Hello Bekka,
    Happened on this page looking for something else. Saw your wondering about predators avoiding things that might taste bad. I have had a lot of experience with South African chameleons (Bradypodion) and have seen them avoid bees and bee mimics AFTER a bad experience, but not before. I also have seen them eat black-and-white Anthomyia spp. flies, even though the stripes should have been aposematic, UNTIL suddenly one eats one that tastes bad, spits it out AND refuses black-and-white striped food thereafter. Presumably the bad one had gut-loaded itself with something bad.
    It is a bigger subject than one at first might think, and I have no quantitative data for you (sorry!) but in biology one must go for the reasonable hypothesis based on anecdotes until the compelling quantitative, controlled results are available, which commonly is never. The idea that the plural of “anecdote” isn’t data is a delusion to be left to the grammarians. Just because anecdotes are harder to employ constructively is no reason to shirk them! 🙂
    Cheers, and thanks for your page,
    Jon

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s