The "Karner" Blue (Plebejus melissa samuelis) is one of the butterflies described and named by Vladimir Nabokov.
The Karner Blue is a small butterfly with an average wingspan of 25 mm. The males are an iridescent violet blue, the females are gray brown often glossed with blue, with a submarginal band of bright orange chevrons to which melissa owes its common name, Orange-margined Blue. The adults live only four or five days. They come in two broods, with adult flights in late May to early June and late July to early August at Karner and throughout the range, settling on moist sandy ground, drinking at puddles and sipping the nectar of Pine Bush flowers. When the Karner Blue was still abundant, it flew in large flocks of hundreds or thousands. The only foodplant its caterpillars feed on is wild blue lupine (Lupinus perennis L.). This makes it a highly specialized insect, vulnerable to changes in the ecosystem that affect the wild lupine.It's interesting, and perhaps counterintuitive, that some of the best places to seek butterflies are not particularly "scenic" to a human eye. I took the upper photo from the top of a hill overlooking Reed Lake at the Crex Meadows Wildlife Area in northwestern Wisconsin. The surrounding countryside appears rather bleak, but it has one crucial feature - an abundance of lupine:
When I got to Crex Meadows, the DNR staff reported that this year an abundance of Karner Blues had appeared, so I was hopeful of finally getting a good photo of this somewhat elusive butterfly on the Endangered Species list. Karner Blues show a sexual dimorphism in their color patterns, the males having beautiful cerulean sky-blue color to the wings on the upper surface. The hard part is capturing that in an image, because they tend to rest with their wings upright:
Shortly thereafter I saw a blue with specks of gold on the upper wing surface - the pattern of the female. This one led me on a merry chase, but finally let me hover above her for her portrait.
I'm hoping someday to locate eggs, caterpillars, and a chrysalis to photograph.