Less than a month ago, I spotted a lone Black Swallowtail caterpillar munching away on the forgotten celery in my garden. Despite several short cold spells, this determined fellow had survived and was going about his business as if spring were around the corner. The next day, the caterpillar was gone, presumably headed off to bed for the cold winter ahead.

Black Swallowtails (Papilio polyxenes) overwinter in their pupal stage, and emerge as adult butterflies when spring arrives. I've searched the garden fence and nearby shrubs, hoping to find a new chrysalis, without success. The Black Swallowtail is well-camouflaged in its brown pupal case. I don't expect to see it again until the warm weather returns.

Learn more about butterflies and moths:

• Characteristics: Order Lepidoptera
• How to Tell the Difference Between Butterflies and Moths
• The Longest Repeat Migration in the Insect World

Photo: © Whitney Cranshaw, Colorado State University, Bugwood.org