Karner blue butterfly densities, resource densities, and resource use at Sandhill Wildlife Area, Wisconsin, 2016

Insects with morphologically different life stages can face a time tradeoff between foraging and egg-laying behavior when larval and adult resources are spatially segregated. Understanding this tradeoff in the Karner blue butterfly (Lycaeides melissa samuelis) can inform resource management for this federally endangered species under changing resource distribution and availability. We collected data on adult butterfly densities, larval (wild blue lupine, Lupinus perennis) and adult (nectaring plants) resource densities, and adult resource use. We defined resource uses as anytime a butterfly was found (resting, crawling, feeding, laying eggs, mating) on a resource. Data were collected in eight habitat patches (10 x 10 m) occupied by Karner blue butterfly adults across an area of about 105 hectares at Sandhill Wildlife Area, Wisconsin during the first and second adult generations. Butterfly surveys were conducted using modified Pollard-Yates transects in each of the eight plots. Samples of lupine and nectar density were taken in each of the eight plots, one at each of the four corners, and one along each side. Lupine and nectar density samples were also taken across the entire landscape, independent of butterfly presence.