Karner Blue Butterfly and Wild Lupine

Karner Blue Butterfly and Wild Lupine

​Wild blue lupine (Lupinus perennis), or sundial lupine, is the only food source for the endangered Karner Blue Butterfly (Lycaeides melissa samuelis). Lupine has tall, light blue-purple spiked flowers and prefers dry, sandy soil. My first introduction to lupine was after taking a trip from my home in central Wisconsin to the Upper Peninsula in Michigan. The lupines were blooming profusely along the roadside. Unfortunately, after some online research, it appears that these are non-native Bigleaf lupines (Lupinus polyphyllus) that outcompete and even hybridize with native lupines and do not support the Karner Blue Butterfly. Bigleaf lupine, native to the western United States from California and Nevada, and north into Canada and Alaska, are not native to the Midwest or East Coast like L. perennis. 

​Because L. perennis is the only food source of the Karner Blue Butterfly and because Bigleaf lupine is outcompeting and hybridizing with L. perennis (hybrids also cannot support the Karner Blue Butterfly), the butterfly has become endangered. Although it was first classified as endangered in 1992, its status has not improved in the past 30 years. In many areas, the butterfly's lack of food source has led to local extinctions. Once found continuously from Wisconsin to the Atlantic states, the Karner Blue is only found in parts of Wisconsin, Michigan, Ohio, New York, and New Hampshire.

Other than non-native lupine encroaching on the native blue lupine’s habitat, factors like clearing land for farming, and development of commercial and residential properties have all played a role in the loss of wild lupine. This is one of the reasons for arguments in favor of planting plants native to your region, no matter where you live. This concept is explored in detail in Doug Tallamy’s book, Bringing Nature Home. If suburban (and any other) landowners would carve out as much lawn as possible and return it to native trees and flowers, then native insects with a specific food source and habitat would have a greater chance of survival. This also directly helps birds who feed on native insects and seeds. Most baby birds, no matter what they eat as adults, require an insectivorous diet to survive to adulthood. There is nothing wrong with having and enjoying a lawn and I will never completely get rid of my lawn because it provides an area for my child and dogs to play. However, I highly encourage adding native plants (and removing invasive ones) to your property to help native birds, bees, butterflies, and other insects.

​In addition to homeowners, as family farms are being bought by larger farming companies, the tree, hedge, and flower rows that used to exist between fields are being plowed under and turned into farmland. These rows of (sometimes) native plants used to provide a respite that native insects and birds could survive in, particularly for migrating birds, providing resting stops and food as they migrated. The loss of even these small habitats can make a huge difference to our native organisms.

​If you wish to help the Karner Blue Butterfly and live in a state where it and wild lupine has traditionally thrived (check the BONAP map) plant native L. perennis. Furthermore, if you have any non-native lupine on your property be sure to remove it before planting native to reduce the chances of cross-pollination and hybridization.

References

1. Prairie Moon Nursery. https://www.prairiemoon.com/lupinus-perennis-wild-lupine-prairie-moon-nursery.html
2. Prairie Nursery. https://www.prairienursery.com/lupine-lupinus-perennis.html\
3. BONAP. https://bonap.net/Napa/TaxonMaps/Genus/State/Lupinus
4. U.S. Fish & Wildlife Service. Karner Blue Butterfly. https://www.fws.gov/species/karner-blue-butterfly-lycaeides-melissa-samuelis