Hosting Butterflies on the Doorstep

Walking out the door one September morning, I saw a tiny black blip at my feet. It was the final molt of a pipevine swallowtail caterpillar, the old, squashed skin (and face!) that drops when a butterfly caterpillar becomes a chrysalis. So, I looked up. And there was the chrysalis, fresh and glistening, hanging from a brick above my head.

- - Joanna Brichetto

Butterfly gardens provide nectar plants for the adults, and host plants for the caterpillars. Here a pipevine swallowtail is feeding on ironweed nectar.

But the best part was when I made my kid look at the black blip, and then he too looked up to find the butterfly-in-progress who dropped it. He knew.

LITTLE CLUES, BIG STORY

The little wad of caterpillar skin tells a big story: the story of a native plant and animal interaction, and of the astonishing specificity of a larval host plant. Here, the plant is wooly pipevine, and the larva is the caterpillar of a pipevine swallowtail butterfly (Battus philenor). Pipevines are the only plants a pipevine swallowtail will lay eggs on because that’s what her caterpillars can eat. The plant and animal evolved together in the habitat native to this place, Nashville, Tennessee.

This is why I grow plants that make new butterflies. And why my boy and I knew what the blip was.