Tuesday, November 25, 2008
A New Type of Butterfly (for Judi)
The Polydamas Swallowtail (also called the Gold Rim Swallowtail) does not actually have a swallowtail, making it "the swallowtailless swallowtail." Go figure. Judi has Polydamas caterpillars feeding on a Dutchman's Pipevine along the back fence. The Polydamas is unique among butterflies in that the female lays eggs in a cluster, rather than singly and spread out, and the caterpillars travel together in little caravans as they feed and grow:
One theory is that by massing together the Polydamas caterpillars look like something big and mean and are less likely to be taken by predators. Here's a group of larger ones grazing shoulder to shoulder:
These caterpillars get really, really big. Also really, really ugly:
When the Polydamas caterpillar forms a chrysalis, it looks a lot like a dead and dried leaf. This little strip of vine features a dead leaf at the top, Judi's first Polydamas chrysalis in the middle, and another dead leaf at the bottom, so you can see how realistic they look:
This is the chrysalis up close:
Judi has three of these Polydamas chrysalises in protective custody at this time, and a bunch more caterpillars still munching away on the vine out back. I hope to have pictures of the emerged butterflies for you in a later post.