Here’s the butterfly—identified

February 23, 2014 • 11:16 am

I guess the readers correctly identified this morning’s butterfly as the Comma Butterfly, Polygonia c-album (also known as the “anglewing” for obvious reasons), though I don’t know how it got that weird Latin binomial. It’s remarkably cryptic, and here’s the picture reader John took when the beast was removed from the background:

Insect2

The white comma-shaped mark on the underwing is apparently diagnostic.

Here’s the dorsal side of the wings (from the Wikipedia entry), which aren’t cryptic at all. One wonders why one side of the wings are so colorful and the other cryptic. If it were poisonous or toxic, and the color was “aposematic” or warning coloration, then both sides of the wings should be colorful. Perhaps it keeps the wings open to attract mates, and folds them to camouflage itself. In that case, though, the females should be completely cryptic, as there’s no advantage to them being bright (I’m assuming males do the displaying).  I found no evidence, though, for such sexual dimorphism. I’m sure at least one reader knows of a good theory for this.

800px-Polygonia_c-album_qtl2

32 thoughts on “Here’s the butterfly—identified”

  1. Wikipedia says:

    The species survives the winter in the adult stage, and adults are of two forms. The form that overwinters before reproducing has dark undersides of the wings, resembling a dead leaf, a perfect camouflage throughout the winter.

    So that would explain the cryptic outside wings but colourful insides since I guess it mostly needs to hide while hibernating.

    Cool looking creature!

    1. We do sometimes see these butterflies in mid-winter when it is un-seasonally warm – I am sure that Diana MacPherson is right that the underwing colour is to hide in winter.

      I see them often in Spring & Summer in East Anglia (the bulge on the East of England) and they are often one of our earliest fliers.

      They nectar feed with their wings outstretched and so are reasonably easy to photograph!

  2. I don’t know how it got that weird Latin binomia

    “c-album” is Latin for “white c”.

  3. My first thought was something similar to what Diana posted: that one side of the wings was far less likely to be seen at rest, so it had little selective pressure to look as much like a dead leaf* as the side usually seen.

    * Only as much as the genes that control pattern and color operate on both sides. I don’t know much about butterfly genetics, but this would predict that they are at least somewhat separated. (My silly analogy is that of needlepoint: there is a lot more pressure to make the display side nice than the non-display side, even though both sides are linked.)

  4. 1. “c-album” means “white c” referring to the mark on the underside of the wings. Polygonia interrogationis, the Question Mark butterfly, is very similar and is also named for the white mark on the underside of the wing.

    2. In Virginia where I grew up, these butterflies were common in early spring, often before there were leaves on the trees. The coloring on the upper side of the wings IS cryptic – the spots help break up the shape, and the warm brown color changes slightly with the angle of the light and isn’t that different from the colors of dead leaves and last summer’s flower stalks.

        1. Oh dear! Even knowing there was a sniper there somewhere, and taking my time over it, I only spotted one of these.

          Bring back the nightjar!

  6. I used to see these fairly frequently when I lived in the south of the UK, but never since I came to Scotland. However, in my garden here I see several of its close relatives: Small Tortoiseshell, Red Admiral, Peacock and Painted Lady. They all overwinter as adults, and all have bright markings on the upper side of their wings and are dowdy below. They emerge in the spring when the temperature is quite low, and are seen also in he autumn when the temperatures are dropping. A characteristic behaviour is that they bask in the sunshine with their wings open. I wonder if the colouring on their upper wings absorbs the sun particularly efficiently, bearing in mind that there might be “colours” in the ultraviolet that we cannot see.

    1. My copy of The Millennium Atlas of Butterflies in Britain and Ireland has a distribution map. The Comma is most common in the south, sightings are less frequent as we go north and it looks like the Comma doesn’t go beyond Hadrian’s Wall.

  7. There is a standard explanation for why this butterfly is bright & flashy on the inside, and camo on the outside. This strategy, seen in many insects, is to present a ‘search image’ to their predators that will not resemble what they look like when they come to rest. Since they can hardly hide from their predators (mostly birds) when in flight, they instead advertize what they want the predator to look for. This butterfly would be saying ‘look at me! I am bright orange and black!’ Then when it lands it folds its wings, and presents a camouflaged form that looks nothing like what the bird would be looking for.

    Here are other examples. There are many species of these, and everyone has probably seen them or something similar.
    Underwing moths
    Banded winged grasshoppers

    3. Might the bright upperwings also serve to induce a startle response in a predator that has spotted them in the folded, camouflaged state? The predator is looking at a mottled, brownish bit of food, and suddenly this bright orange thing takes off.

  8. Many butterflies’ under-wings are dull-coloured, in sharp contrast to their over-wings. When they settle down on a leaf or anything else, they keep their wings up against each other, only showing the under-wings, so I think your camouflage idea is probably right.

    Moths, on the other hand, never fold their wings together but always hold them splayed out.

    2. Thanks for the note on how butterflies and moths rest differently. Any other way to tell them apart? (Besides leaving them with my wool clothes.)

      1. You can safely leave them with your wool clothes, unless they are clothes moths, then better not…
        As for telling moths and butterflies apart, taking a look at their antennae helps. Butterflies generally have long and thin antennae which get thicker at the end, while moths tend to have antennae which are thicker in the middle and often feathered. Plus, some moths can rest their antennae along their sides – as far as I know, butterflies don’t do that.

        1. I apologize for not thinking to look this up for myself, and I am grateful for the answers given me here.

          Now I have to go find out what a “skipper” is. Probably something peculiar to Australia.

        2. Phylogenetically, butterflies are moths, i.e. the ‘moth’ clade is just Lepidoptera and the butterfly clade is nested within it, closer to some moths than others.
          Similarly, bees and ants are wasps; birds are dinosaurs; snakes are lizards; you are an African ape and also a jawless fish. Etc.

      3. I was not referring to the little moths whose larvae feed on wool (and other natural fibers) or on starch (in flour, cereals, etc.) but to the vast plethora of night moths, many of which are very beautiful despite the fact that their colours are dull compared to butterflies.

        See http://en.wikipedia.org/wiki/Moth

  9. I’ve seen blue morpho butterflies in Venezuela. When they fly, you see a flash of blue, then they disappear against the jungle background, then you see another flash of blue. It is not easy to track one in flight.

    1. It’s an interesting site to look at, but it’s a bit of a pain to submit things there. At least, it was a couple of years ago. Commandline FTP, and an assumption you were fluent using taxonomic keys. Both of them about as alien as it gets for most photographers.

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