Third, fourth, and fifth instar larvae are similar in their exuberant appearance. The body is very large, with fifth instar larvae reaching up to 4.5 inches in length. Color is bright green or sea green with prominent dorsal protuberances, all with distal black spines. Thoracic protuberances are orange to red, abdominal protuberances are yellow, and side protuberances are pale blue.

Lake Redman
York County, PA