Northwest Butterflies: New Caterpillars

Whenever you come across a patch of nettle, if you dare to brave the stinging plants, look for leaves that have been folded up or down, and you'll likely find a butterfly larva hiding inside. Milbert's Tortoiseshells (Aglais milberti) lay their eggs in masses under nettle leaves, and when the larvae hatch, they tend to feed in large groups, becoming more solitary as they mature. While these larvae tend to be more visible on nettle, they frequently use silk to fold the edges of a leaf together, with the edges facing up (top side of the leaf inside the "tent"). Red Admiral (Vanessa atalanta) and Satyr Anglewing (Polygonia satyrus) larvae are usually solitary, and fold their leaves down (underside of leaf facing inside the tent). Until this past weekend, I've only found a few Red Admiral larvae, and frequently come across Milbert's Tortoiseshells, but have never seen any Satyr Anglewings. I was thrilled to find two 4th instar larvae (out of 5; instars are larval stages before they pupate) in Schnebly Canyon, along with several masses of 3rd, 4th, and 5th instar Milbert's Tortoiseshell caterpillars. The next day I traveled up Reecer Creek to collect some nettle before heading home with my cat's, and found at least a dozen 3rd instar Satyr Anglewings. I kept about five of them, so that I can photograph the different stages, the pupae, and the fresh adults. Read my last blog post for more information about the trip where I found these little guys.