Gynaephora groenlandica, the Arctic woolly bear moth, is a lymantriid moth found within the Arctic circle, in Greenland and Canada. It is best known for its very slow rate of development. It was once estimated that it had a 14-year lifecycle from egg to adult moth, unique among the Lepidoptera with the ability to withstand temperatures below −60°C. The larvae degrade their mitochondria in preparation for overwintering and resynthesize them in the spring, and each instar of the caterpillar takes about a year. Subsequent studies have revised the lifecycle duration to be 7 years.