Appearance

• Male and female Karner blue butterflies have a 1-inch wingspan. The males' topsides are silvery or deep blue with black margins, and the females are grayish-brown to blue, with orange crescents inside their thin black wing borders. Both sexes are gray underneath with orange crescents along the edges and scattered black spots edged with white.
  
  

Habitat

• These butterflies live in Indiana, Wisconsin, Michigan, Minnesota, New Hampshire and New York. Previously they had lived in 12 states. They were placed on the federal endangered list in 1992. The caterpillars only feed off wild lupine leaves. Wild lupine only grows in savannahs, prairies and other increasingly rare places with sandy soil. The adult butterflies feed off the nectar of flowering plants, which severely restricts where they can survive, the U.S. Fish and Wildlife Service explains. Natural disturbances keep encroaching forests at bay and help wild lupine grow, but they are now few and far between.
  
  

Reproduction

• This species usually hatches twice annually. The first group hatches in April from eggs laid the previous year. According to the Michigan Department of Natural Resources and Environment, the caterpillars have a mutual relationship with mound-building ants, excreting a sugary substance that the ants consume and, in turn, receiving predator protection from the ants. In mid-May, the caterpillars pupate. By the end of May or early June, the adult butterflies emerge. The adults then mate and lay their eggs in June on wild lupine plants.
  
  

Protection

• The federal government is following a recovery plan to increase species numbers. Zoos are raising these butterflies and reintroducing them to places where they used to live, such as Ohio and Indiana. Indiana Dunes National Lakeshore in the northwestern part of the state is an outdoor lab that studies plant succession and includes wild lupine and Karner blue butterflies. Some prescribed fires are helping to restore habitats. Research is also ongoing to find the best ways to manage the species and its habitat in order to remove it from the endangered list. Wisconsin instituted a statewide habitat conservation plan that allows human activities that do not disturb these butterflies and their habitats.
  
  

Individual Measures

• The Michigan Department of Natural Resources and Environment states that individual landowners can help protect and restore the Karner blue butterfly through conservation and specific property management means that encourage wild lupine growth, educating others about the species and limiting or avoiding the use of pesticides in or near known Karner blue habitats.