Wednesday, September 24, 2008

Shape-Shifting Chrysalis


Perhaps unaware that its skin has popped off, the chrysalis continues its wild loops. Perhaps it's just exulting in the last motion it will be able to execute before it hangs, motionless but transforming, for the next 14 days.
You can see its beaded antennae, running from the eye (at the bottom of the chrysalis) along the leading edge of the wing. You can see the veins in the wing, and the segments in its fat abdomen.

Here's a sequence of pictures that shows how the chrysalis changes its shape in the course of only an hour. It starts out still vaguely cylindrical, reminiscent of a caterpillar.
It writhes and pumps and changes as it hangs.The whitish line on its midsection moves up as most of the bulk moves higher into what will be the butterfly's abdomen. It's starting to assume the tapered shape of a mature chrysalis. (see the right-hand one for comparison).

But for the ravishing seafoam-green color, the fresh chrysalis on the right is almost there:
Over the next day, the whitish buttons on the midline and around the tip will brighten to burnished, 24 K gold finish. I don't understand or know how an insect creates the hue and sheen of iridescent gold, but it does, and I am in awe.

We let this caterpillar choose a place close to another chrysalis to hang and make its transformation. However, at this point it's possible to detach the silk anchoring the chrysalis with a sharp X-acto knife, and with a dot of Elmer's glue, attach it wherever you wish. The important thing is that the chrysalis hang absolutely clear of any obstruction such as a twig or terrarium side. The emerging butterfly is weak and must hang clear of obstacles, or its wings could dry crumpled, rendering it flightless. So a thin twig is ideal for anchoring the chrysalis.
Here, the glue is drying. When it hardens, I'll hang the chrysalis up where it can get light and air, to remain undisturbed for a couple of weeks. I'll spray it with a mister from time to time, but that's about it. The chrysalis has work and much magic to do.

If you like these photos, just wait 'til you see what I captured this morning. We have a butterfly to look forward to!

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