The Karner Blue was originally found in a narrow belt from Minnesota to New Hampshire and then North into Ontario. The species has been extirpated in Ohio, Pennslyvania, Maine, and Ontario. The Karner Blue is a small and radiantly colored butterfly.
Males are a light blue with silvery indigo colored wings.
There are two generations per year. Habitat The Karner Blue prefers sand prairies and oak barrens. They inhabit areas with few trees, but a sufficient growth of wild lupine is essential. Periodically the lupine must be maintained by fire. The Karner Blue appears to have an association with ants during the larval stage.