Tuesday, November 25, 2008
The Transformation of a Sulphur
This series of photos illustrates part of the process that a member of the Sulphur family goes through to form a chrysalis and emerge as a brilliant yellow butterfly. Judi and I have taken pictures of a lot of such transformations, and this series combines photos from several different butterflies, hence the different backgrounds. As usual, you can click on any of these pictures to see a larger version.
This is how they start: A small caterpillar crawling, in this case (by accident), on my shirt:
Lots and lots of eating later, the much larger caterpillar attaches itself to a branch using some incredibly tough threads and hangs in the shape of a J:
The transformation from caterpillar to chrysalis takes place inside the skin of the caterpillar, while the encasing skin becomes shiny and thin:
Then the tender chrysalis convulses until the outer skin, that was protecting it, splits and is shed. In this picture, the dark ball above the chrysalis is the shed outer skin. The chrysalis itself is still soft at this point and hasn't settled into its exact final shape:
In a few hours the outside of the chrysalis is hard, and it hangs for weeks while the butterfly forms.
When the butterfly is finally ready to emerge, the outer shell of the chrysalis starts to become thin and transparent, and the butterfly inside starts to become visible. In this picture, you can begin to see the orange spots on the wings that will make this an Orange Barred Sulphur:
In this picture, the chrysalis in front (there's another behind) has become so transparent that you can see the yellow of the wings, and vaguely make out the head (pointing down) and the ribbed abdomen (pointing up):
Now you can see the butterfly in there pretty clearly -- even its yellow eyes and the veining on its wings. It's ready to come out (it's worth clicking on this one to see the larger version):
...and now it's out, hanging from the now-empty chrysalis until its wings expand and harden:
These are the butterfly's underwings as it sits on Judi's fingers and comtemplates launching on its first flight. It's very hard to get a picture of this butterfly's overwings, because they never spread their wings unless they are in flight, and then they're moving like a pinball in a pinball machine, except it's a three dimensional pinball machine:
In case you want to get up close and personal (another one you might want to click on for the larger version):