7/8-1 1/4" (22-32mm). Male above has all wings blue with fine black borders and white marginal fringes. Female above is brown (often with blue highlights), with bold orange band at wing margins. Below, both sexes light brownish white, with numerous white-bordered black spots
on inner 2/3 of wings and black-bordered orange submarginal border.
The Karner Blue, a subspecies of the Melissa Blue, is on the U.S. Endangered Species
List. It is classified as endangered in Illinois, Indiana, Michigan, Minnesota, New Hampshire, New York, Ohio, and Wisconsin. Like so many endangered species, this butterfly has been the victim of loss of habitat to humans. Each type of butterfly relies on particular plants for feeding and laying eggs on. The Karner Blue can't live without Wild Lupine, a plant that has become increasingly rare in the eastern U.S. Development has overtaken the lupine's habitat in many areas, and fire suppression affects its habitat in others, allowing forests to encroach and shade out the lupines and other meadow plants. The Karner Blue declined alongside the lupine, and then its small populations were further reduced by collectors, who wanted the rare and beautiful butterfly for their collections. While recovery plans are being drawn up for the Karner Blue, the butterfly receives protection in several federal and state preserves.
Northern Blue very similar, but with orange bands of female above and both sexes below usually not as wide or as bright as those of Melissa Blue. Other similar species lack orange on forewings below.
Egg cushion-shaped, light green with white ridges. Caterpillar sluglike and covered with fine whitish hairs; green (darker on back), with yellow-cream stripe along sides. Chrysalis yellow-green to green with fine yellow spots. Host plants vary with location and subspecies : various members of the pea family in the West; lupines in the East.
2-3 broods; spring to autumn, depending upon latitude.
Mountain meadows, shrubland, and prairie in the West; pine-oak barrens in the East.
Central Alberta to central Manitoba and south to southern California and western Texas for western populations; eastern Minnesota to New Hampshire in scattered colonies for eastern populations.
Eastern populations of the Melissa Blue are known as the Karner Blue and are endangered throughout their range in the northern Midwest and the Northeast. Some biologists think that the Karner Blue (because of its geographic separation from the western populations and different food and habitat requirements) is, indeed, a separate species from the Melissa Blue.