It’s spring and Red-spotted Purple caterpillars are venturing out of their winter hibernaculums. Partially grown caterpillars created these safe retreats last fall by silking a tiny leaf shut, silking the leaf to the tree, then crawling inside and going to sleep for the winter. All the other leaves fell from Black Cherry trees and Beach Plum bushes, but the hibernaculum leaves remained still attached – a tell-tale sign to a keen naturalist that some creature might be inside.
As temperatures warm, these teeny tiny caterpillars (about one-quarter inch long) are venturing forth, sunning in the warmth and looking for tasty buds on their host plant (Black Cherry, Beach Plum, . . .).
Around homes, as treasured wood piles are dismantled for firewood over the course of a winter, possibly quite a few Mourning Cloaks, Question Marks, and Commas are disturbed from their slumber on brutally cold winter days and meet their demise.
To ensure the survival of these unique butterflies that overwinter as adults, consider building a Butterfly House.
Learn how easy it is to build a Butterfly House by reading my latest column at Native Plants and Wildlife Gardens.
On September 23, 2012, I watched one of the very last Red-spotted Purples in the garden. It danced around the Beach Plums and I thought it must be laying eggs. I looked closely at leaf after leaf, zeroing in on the very tip where Red-spotted Purples carefully lay their jewel-like egg, but could find none.
As I scrutinized the leaves I spotted a different treasure than expected – a teeny-tiny caterpillar silking a bit of leaf to the branch and silking the leaf curled shut.
I stepped back from the Beach Plum, looked at the bush as a whole, and noticed other similar leaves . I knew just what I was looking at, though I’d never seen one before – a nearly completed HIBERNACULUM, where a partially grown Red-spotted Purple caterpillar would winter, hopefully safely.