The Karner blue butterfly is one of nine species of butterflies on the North American Endangered Species List. Lycaeides melissa samuelis is a subspecies of the Melissa blue butterfly. The Melissa blue is found in the western half of North America where the Karner subspecies is found in the Great Lakes Region. The reason why the Karner blue has decreased in population is because it is very specific in the larval host food. The Melissa blue caterpillar feeds on various plants in the pea family. The Karner blue caterpillar feeds only on lupine which because of habitat loss and fire prevention has been decreasing in the Karner blue's natural habitat. As the larval host plant declines there is less food for the Karner caterpillars and so their population declines too. Fortunately there are still some places where the Karners thrive. This photo was taken at the Necedah NWR in Wisconsin. Necedah has one of the highest known Karner populations around, including this pair that was doing their part to increase the species population.