Watching Metamorphosis in the Vines

The surprising journey of the Gulf Fritillary butterfly as it progresses from egg to butterfly

The passionflower vine grew in front of my house for years before the butterflies found it. But once they did, they couldn't get enough of it. In the winter of 2019, no hard freeze killed the vines to the ground, unlike every year since 2021. And in early spring, I suddenly discovered 7 chrysalises hanging from the lattice in front of my house.

This came as a complete surprise to me, but a very welcome one. Through that spring, I was able to witness all but one of the phases of the Gulf Fritillary metamorphosis.

A Mystery

The process has to begin with an adult butterfly laying eggs. Once the cycle is underway, it's easy to see where the adults come from. But after a killing freeze - one that, according to entomologists, should wipe out all the Gulf Fritillaries in the area - where do the new adults come from? Come back they do, however, sometimes very early in the spring.

The mystery is how they manage it. Most years they reappear so quickly that I suspect they have survival tricks still unknown to science. The story goes that they migrate from farther south, but those killing freezes usually reach pretty deep into the state. At least a few must find a warmish spot to wait out the cold. I tried saving a chrysalis one winter, but it got eaten. Experiment aborted.

The Process

So the process starts with the adult butterfly laying eggs. She usually lays them on a tendril or at the tip of a stem. Much to the dismay of the plant, these are the easiest parts for the caterpillars to eat. The newborn caterpillars are quite tiny - remarkable to see how big they get in a short period of time.

[Picture: Gulf Fritillary butterfly drying out after emerging from the chrysalis it hangs from.]

The caterpillars the wasps and wrens don't eat will go on a trek once they're big enough, slowly crawling along to find the right spot to make a chrysalis. It can be from the trellis, from the roof, in the vines. Once found, they attach one end, hang down, then shed their spiky outer coat. I sometimes find a chrysalis by first spotting this caterpillar coat debris on the ground.

The finished chrysalis looks much like a dead leaf. And to my amazement, I found they are conscious in this phase! If you barely touch them, they move. I once found one vigorously shaking back and forth. Looked it up to find they can do this when they perceive a predator threat. How in the world can something be aware when it's just a bunch of goo? I guess if slime molds can do it, it's not so strange for caterpillars.

After a little over a week, they emerge. I was never able to actually see one break out of the cocoon - this was the phase I missed. But I have often seen them hanging from the cocoon, drying out, before their first flight. They're still a little wobbly at first, and stop often to dry out more for a short while. Then they are ready to do their part to start the process again. And life goes on...