As mentioned in my earlier post, there were signs that the Eastern Tiger Swallowtail was approaching the final phase of its growth before metamorphosis. Little did I know that what happened after its dramatic color change would be quite a shocker…just in time for Halloween, the headless caterpillar!
First, let me assure you that nothing (unnaturally) violent happened to the caterpillar. But its head did fall off. All joking aside, while that’s how it looked, what actually happened is that the caterpillar performed its final molt, which is when it pupates: the chrysalis is its form after the last molt. Finding the dried-up husk of its head with the empty eye spaces was a bit jolting.
The other unexpected turn of events was that the caterpillar didn’t hang from its back legs, forming the commonly-seen “j” shape, and then pupate; instead, it spent a lot of time traveling throughout the container, looking for just the right spot…and settling on a tulip poplar twig (as I’d hoped), with its head facing up. It then anchored itself to the chosen spot with silk at its back legs as well as creating a “sling” of sorts to hold its main body in position.
After further research, I discovered that this is actually a normal position chosen by some caterpillars. While it’s not what I was expecting, it’s a relief to know that it knew what to do.
The caterpillar, now sans head, really isn’t identifiable as a caterpillar anymore. Even stranger is what’s going on inside the chrysalis: processes that transform the caterpillar body into a butterfly. Wondrously, the caterpillar’s cells are being broken down and then formed into something new. Science nerds, celebrate the sheer awesomeness with me.🤓
Now a few days after the caterpillar began to form its chrysalis, it looks exactly like a tulip poplar twig, down to the spot in its “head” area where it mimics the broken end of an actual branch. Amazing!