Saturday, June 2, 2012

The Moth that mimicked the Butterfly

Hey ya'll 

In most individual's minds, the butterfly is almost always contrasted with the moth. The butterfly, supposedly being the more beautiful of the two flies exclusively during the day and is wonderfully patterned. The moth, in comparison is often depicted as being ugly, or dull, and flutters about in the shadows of the night. Now, while this has no doubt helped most people with the general classification and distinction of a butterfly and a moth, the reality is quite the opposite and these arbitrary classifications (while applicable for a large majority of the species) are not always the truth. Butterflies are not always colorful, and moths, not always dull (arguably one of the most beautiful lepidoptera in the world is the Madagascan Sunset Moth Urania ripheus whose rainbow colored wings have become iconic somewhat for light refraction on lepidopteran scales). And just as not all butterflies fly exclusively during the day (a quick Google search revealed that some butterflies like the Caligo Owl Caligo sp. do indeed fly at night), not all moths stick to the cold, dark shadows of the night. Indeed, there are moths that are diurnal and the Sunset Moth can perhaps be argued to be one of these.

But more interesting than that, perhaps, are moths who have taken so much to the wonderful day-time world of sunshine and flowers that they have gradually begun to mimic butterflies! It's quite easy to romanticize all of this and concoct a tale that the moth, madly jealous of his beautiful cousin the butterfly, one day decided to put on her clothes and parade about in all his imitated glory, but the truth is that mimicry often takes place to ensure these insect's survival. Consequently, many of these day flying moths seem to mimic Atrophaneura swallowtails, Danaiidae, or any other amount of butterflies that are recognized as toxic or unpalatable to predators in a process known as Batesian Mimicry (where a supposedly harmless animal mimics the appearance of toxic or dangerous ones to avoid predation). The actual mimic, when one looks at it, can really be quite stunningly similar to the "original" animal and over time (through evolution, variation, and other complicated processes that are still too difficult for my non-scientific-background brain to process) produced a wide range of animals all resembling various forms of each other all for the purposes of survival. Fascinating, isn't it!!! Either way, most of this would be purely theoretical for me if not for an incident that happened a week ago when I myself was quite nearly fooled by a Batesian Mimic myself.

It happened when I was wandering the grassy area next to the University (now my place of employment). As is personal custom, I always make it a point to stroll around the area for several minutes every day in search of "something new" before I make my way to my car. As it turns out, I did find something that caught my eye. A red-bodied swallowtail of the genus Atrophaneura, surprisingly small for it species, fluttering just several centimeters above the tall grass. This, on its own, would have already been quite a find to me (Atrophaneura sp. is almost never found in this area as they prefer more shaded, forested habitats with an abundance of aristolochiae vines upon which to feed) so imagine how my surprise was compounded when I netted the fluttering creature to find that it was in fact NOT a swallowtail butterfly, but a medium-sized moth! In rest, the moth holds its wings flat over its body (as is "traditional" with moths) and resembles something as unremarkable as a pitch black "triangle". But when disturbed or startled, the moth quickly raises those unremarkably dark fore wings to reveal a strikingly iridescent set of blue under-wings, set against the stark contrast of a brilliant pink-red abdomen.
The moth, which has since been identified as Histia flabellicornis ultima
Being quite partial to swallowtail butterflies (or the genus Papillionidae, in general) myself, I fortunately had many specimens of Atrophaneura (to which the red body is characteristic as a warning sign to birds that the butterfly is poisonous) with which I could compare it to and decided ultimately that this particular species of moth seeks to mimic the Common batwing, or Atrophaneura varuna.
Dorsal view of the Common Batwing Atrophaneura varuna (male) 
Dorsal view of the Common Batwing Atrophaneura varuna (female)
Arguably, there is a striking difference between the two specimens in that the body of the batwing is a velvety black-blue and not red but I think that may have something to do with the fact that the moth may not itself be poisonous/unpalatable to predators and birds and therefore, has a greater need to flash these red warning colors more explicitly. If you were to compare the moth's red abdomen to the ventral view of the abdomen of the batwing, however...
Ventral view of the Common Batwing Atrophaneura varuna (male)
Ventral view of the Common Batwing Atrophaneura varuna (female)
The resemblance is really quite uncanny. What is more remarkable is also the fact that the level of mimicry does not stop there, at the adults. Indeed the larvae (and I had to grab these images off google because I have not raised EITHER insect on my own) themselves exhibit this sort of Batesian mimicry as well.
Histia flabellicornis ultima larvae
Atrophaneura sp. larvae.

It really is quite spectacularly outstanding (and the moth was such a dear when I picked it up that I almost did not have the heart to collect it) and I hope to be able to add these beautiful moths to my breeding list sometime in the future, but aside from that, there's little more my limited knowledge can tell you about these wonderful insects. If you would like to know more about Batesian Mimicry, though, and the kinds of butterflies and moths that are into this sort of thing, I suggest you hop by Brittanie's blog. She has a very devoted fixation with Heliconius butterflies which are, sort of the poster-boy for lepidopteran mimicry.


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