Can the Karner Blue butterfly be saved?

A male and female Karner Blue butterfly. Photo credit: Ilya Raskin

Diane Turner, Conservation Technician and Outreach Assistant 
​
​The Karner Blue butterfly (Lycaeides melissa samuelis) was federally listed as an endangered species in 1992. This butterfly has a wingspan of only about one inch. The male has silvery or dark blue markings on its wings while the female is grayish brown bands of orange crescents.

Karner Blue butterflies are found in the northern part of the range where wild lupine grows native. The butterfly is most widespread in Wisconsin and can still be found in portions of Indiana (northern), Michigan, Minnesota, New Hampshire, and New York.  Although Karner Blue butterfly habitat used to stretch across 10 states, it has now been eliminated from at least five of those states. 

---

The caterpillars of the Karner Blues, like many butterflies, feed on one plant species, wild lupine (Lupinus perennis).  This native naturally grows within the pine barrens, is the Karner caterpillars only food source. The habitat of the Karner Blue butterfly is tied to that of wild lupine, a plant with a tall blue spike covered in small flowers, which the butterfly relies on as a caterpillar. The plant grows near pine and scrub oak scattered among open grassy areas. Because of their reliance on the wild lupine, the decreasing presence of the plant due to urbanization, decreasing wildfires and other factors have made it challenging for the butterfly to find suitable habitat.

​There are usually two hatchings of Karner Blue butterfly eggs each year. The first group of caterpillars hatch from eggs in April to early May from eggs that were laid the previous year. The caterpillars feed only on wild lupine plant leaves. About mid-May, the caterpillars pupate and adult butterflies emerge from their cocoon-like chrysalis by the end of May or early June. These adults mate, and lay their eggs in June on or near wild lupine plants. The eggs hatch in about one week and the caterpillars feed for the next three weeks. Those caterpillars then pupate and the summer's second generation of adult butterflies appear sometime in July or the beginning of August. These adults mate and lay the eggs that will not hatch until the following spring.

Karner Blue eggs. Photo credit - orionmagazine.org

Karner Blue caterpillar. Photo credit - Science Stock

Karner Blue adult. Photo credit - animalstime.com

Male butterfly on wild lupine. Photo credit: manchesterinklink.com

​
Many federal, state, and local agencies are working along with other partners to protect populations in their current habitats, as well as reintroduce the butterfly to habitat where it had historically been found.

A couple states are finding success in recovering populations of this tiny butterfly. Wisconsin and New York have attributed their success to the use of fire to manage the sandy landscape and the planting of blue lupine, the hearty plant on which larval Karner Blues feed during their short lives. A key factor has been the decision to burn key habitats every three to eight years, so pine and scrub oak don’t grow large enough to shade out the wild blue lupine, which requires direct sun exposure and, because of a deep root system, isn’t killed by fire.

---

For more information, see the following websites.  
​www.prairiefrontier.com
https://esa.npca.org/karner-blue-butterfly/