Bagworm emerging from its case (or bag)

Bagworms are the larval (caterpillar) stage of a moth that is rarely seen. Only the males develop into typical moths capable of flight. The adult female is grub-like and remains inside the bag until just before she dies. Bagworms pass the winter as eggs inside the bag that contained the previous year’s female. In mid to late May the eggs hatch, and the tiny larvae crawl out from the end of the bag in search of food. By using silk and bits of plant material, they soon construct a small bag around their hind part that looks like a tiny, upright ice cream cone. As the larvae continue to feed and grow, they enlarge the bag enabling them to withdraw into it when disturbed. Older larvae strip evergreens of their needles and consume whole leaves of susceptible deciduous species, leaving only the larger veins. The bag is ornamented with bits of whatever type of vegetation they are feeding upon.