From Beast to Beauty

It has to get ugly before it gets pretty.

~Nicholas Sparks
Red-spotted purple adult

Red-spotted purple butterfly (click photos to enlarge)

Well, that is certainly the case for at least one species of butterfly here in the woods… the red-spotted purple, Limenitis arthemis astyanax. This common species is probably not considered beautiful by most observers during its pre-butterfly stages.

rsp-early-instar

Early instar of red-spotted purple caterpillar

It is a bird poop mimic throughout its early life, especially from the third instar larva all the way through the chrysalis stage.

rsp-middle-instar

The larval stages are bird poop mimics with light splotches on a dark background

red-spotted purple last instar

Last instar red-spotted purple caterpillar

I found a late instar caterpillar on a wild cherry recently and decided to watch it in hopes of finding the chrysalis when it crawled away.

Red-spotted purple prepupa

Pre-pupa of red-spotted purple (note silk pad attachment point at rear of body – top in this photo)

The next day the larva was gone. They often crawl off the plant where they have been feeding and look for a vertical surface to climb. They make a silk pad, attach themselves and hang from it, forming a pre-pupa that lasts about 24 hours. Then, the last molt of the caterpillar skin occurs, revealing the chrysalis. Luckily, I discovered the pre-pupa attached to the basement door frame. The caterpillar had crawled a distance of about 25 feet. The next morning I hoped to see the chrysalis.

Red-spotted purple prepupa parasitized

Dead pre-pupa the next morning

But, what I found instead was a dead, blackened pre-pupa. I have seen this shriveled black appearance in other caterpillars when they have been parasitized by various things from tachinid flies to a virus. I watched it the next couple of days and never saw any sign of something emerging, so I am guessing this is a viral infection of some sort that killed this particular larva. I was disappointed, but, to my surprise, I discovered a chrysalis a few days later while pulling weeds in the front yard.

Red-spotted purple chrysalis

Red-spotted purple chrysalis (still a bird poop mimic)

The red-spotted purple chrysalis looks like damp bird poop hanging from a twig. One odd feature is the small round disc that sticks off the side of the chrysalis at about the mid-point. I have never been able to figure out what this is in relation to the butterfly that emerges. I decided to try to keep tabs on this pupa over the next few days to see if I could get lucky and photograph the newly emerged butterfly.

Red-spotted purple butterfly freshly emerged

Freshly emerged red-spotted purple butterfly

Sometimes you just get lucky, and the next morning when I checked, there was a freshly emerged butterfly clinging to the shell of its chrysalis. They usually hang on for an hour or so while they pump fluid into their wings (via the veins), and allow the wings to become firm for flight. This one’s wings were fully formed, so I found it just in time to get a few images.

Red-spotted purple butterfly freshly emerged close up of head

A closer look at the head of the butterfly shows a coiled proboscis

I moved around taking photos. The butterfly occasionally moved in response, flapping its wings in preparation for its initial take-off. The colors on fresh butterflies are so vibrant!

Red-spotted purple butterfly freshly emerged 1

The colors don’t quite match the butterfly’s name

But, admiring this fresh beauty reminded me that the colors don’t really match the rather odd name of this common species – the red-spotted purple. I wonder why it isn’t called the orange-spotted blue butterfly instead. And, come to think of it, while I am renaming things, perhaps I should change the title of this post to From Poop to Pretty. Both changes are perhaps a bit more descriptive of the unusual life history of this fascinating insect.

6 thoughts on “From Beast to Beauty

  1. Wonderful post! I had never seen the red-spotted purple butterfly until moving here (the Eastern Shore). I’ll keep a closer eye on the “bird poop” on the wild cherries from now on. 🙂

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