Caterpillar

Caterpillar

Friday, May 10, 2013

The Swanflower and the Swallowtail

We're back folks, and activity here on the ground has wound down considerably. In fact, nothing at all is happening at the moment. At least, that's how it appears. There is no evidence of the caterpillars or of the ravenous rampage with which they decimated this tiny stand of Swanflower plants. But that's how this curbside microcosm seems to work.

At best, the leaves and flowers of the plant are difficult to spot mixed in, as they are, amongst random weeds and grasses. But after 8 or 10 of the marauding larva have had their way with them, it's difficult to spot even one leaf of the Swanflower plant.

So while we're waiting for the plants to grow, let's review what I have learned, discovered, surmised,  or made up about this interesting co-mingling of life cycles, shall we? And fear not, I won't bore you with parenthetical references, end-text citations, or, frankly, any documentation of scientific accuracy whatsoever. That's the beauty of being a back alley biologist.

But enough about me and my scientific bohemianism. Let's try to stay on task here. The plant in question that goes by the street name Swanflower is, in fact, one Aristolochia erecta. This is just one of hundreds of species in the genus Aristolochia, a member of the family Aristolocheacea. This family has a number of aliases, including "Dutchman's Pipe" and "Birthwort" family. Both of these common names refer to the interestingly odd shaped flowers common to the family. These structures have been described as being shaped like a pipe or a birth canal, depending on one's perspective I suppose.

While the flowers of many Aristolochia species are large and flamboyant, our little hero, the Swanflower, is beautifully understated and subtle. It creeps along on the ground, blending in with the various weeds and grasses found in our study area. Our "study area", by the way, is an approximately 2'x8' patch of green between the sidewalk and the street. It is a glamorous spot, being next to where the garbage cans wait for their ride on Fridays. But, apparently, it will do, as the flowers and leaves appear and disappear in flushes from approximately March to November, give or take a few months.

Our flowers are rather small, approx 4-6. and stand straight up, hence the species name "erecta". The flower is shaped in such a way that a small gnat can skinny his way in to get whatever he is after. Apparently there are hairs inside the flower that prevent the insect from backing out of the tube until he has pollenated the flower. The kidnapping hairs then wilt and the bug can go back about his business. Presumably he will fall for the same trick with another flower.

After only a day or so from when the flower opened, it appears wilted and closed up. Soon the top of the flower totally wilts and falls away, leaving behind what will become the seed pod. This will eventually dry out and split open, allowing the neatly arranged, triangular seeds to spill out onto the ground.

Often, however, the poor little flower never gets to the seed spilling stage because it gets discovered by a gang of small, insatiable, orange/black/brown/red dragon looking caterpillars. As is the case on the ground at the moment, they can completely deforest the little stand of weird looking plants until the next good rain or until the tiny caterpillar farm lays fallow for a while.

Oh sure, that's all well and good for the plant's life-cyle, how about the caterpillar? What's his/her story, you ask? Good question. Thanks for asking it, by the way. It's nice to have an engaged audience!

While the crazy looking caterpillar seems to appear out of nowhere, the fact is that it comes from somewhere. That somewhere is from Battus philenor, but his friends call him the Pipevine Swallowtail Butterfly.

The Pipevine Swallowtail Butterfly is a handsome creature, and flutters around all foot-loose and fancy-free like it owns the joint. It's circuitous route might look like random meandering, but there is method to the madness, as in most things except, apparently, for this blog.

Anyway, these butterflies lay their tiny orange eggs in clusters on the leaves of a few choice species of Aristolochia, which they can then devour upon hatching. The flowers and leaves of these plants contain toxins that, in turn, make the caterpillars toxic to would-be predators. Apparently, their bright coloring is a sign equal to a skull and cross bones, but in bird language. So the poisonous larvae are able to lounge around the buffet, free from the risk of death from above, or at least from birds. In our case, "death from above" is more likely to come in the form of a shoe of an oblivious and heavy-footed human. But everything has it's risks, right?

So far, in our very official study area, once the caterpillars get a certain size, they disappear, presumably to make a chrysalis in which to do their whole transmogrification thing. But I have not seen one of these cocoon-like structures anywhere on the property. So, of this part of the story, I have no photos or evidence, and even less knowledge than what has already been demonstrated.

OK, so I am tired of writing this, which means you, good reader, surely are tired of reading it. But if you are still with me, thanks for your patience and for your mild to medium interest. The fact that you are still reading this is evidence that we share an interest in random biological phenomena. This could be the beginning of a beautiful relationship. And if not, it was nice chatting with you. In any case, I hope to see you back here in the back alley sometime soon. There are more mildly interesting ramblings to come...




Cute little bugger, don't you agree?


Immature Swanflower (will open in a day or two)


Immature Seedpod


Mature Seedpod 


Seedpods and Leaves of Aristolochia erecta


A Pipevine Swallowtail caterpillar in a dark mood...
 perfect time for comfort food



Thursday, April 25, 2013

Tales of the Back Alley Biologist


The Pipevine Swallowtail Butterfly (Battus Philenor) and the Swanflower plant (Aristolochia erecta) have been carrying on an interesting relationship in my front yard for a number of years now. I have finally decided to tell their story. I plan to do so here on my new blog about random science issues that I  like to observe, ponder, and discuss ad nauseum.

I do have some scientific training, having graduated an eon ago from an obscure liberal arts college with a degree in biology. But instead of a BS (Bachelor of Science), I got the somewhat watered down BA (Bachelor of Arts) in Biology, which is sort of a science degree for the mathematically challenged. I don't even care that a lot of hardcore academics and science professionals consider a BA in Biology just a few steps above someone who almost finished reading Biology for Dummies Vol 1.

So I don't exactly claim to be a scientist. I'm more of a Back Alley Biologist.
And I'll keep you posted about the situation here on the ground. Stay tuned...
Swanflower with Pipevine Swallowtail Butterfly larva
The hungry caterpillars hanging out on the Swanflower leaf will be the size of your pinky in a few days

Swanflower (Aristolochia erecta)

Caterpillar of the Pipevine Swallowtail  Butterfly (Battus philenor)