Lupine signal Karner blue butterflies may be near
By Ken Blomberg
Years ago, No. 1 son worked as a summer wildlife technician at Fort McCoy in Monroe County. If memory serves, while working with the wildlife management crew he was involved with research on Blanding’s turtles, wolves, snakes, invasive plants, wild lupine and Karner blue butterflies.
When the flowering lupine plants went to seed, the crews collected and dried seeds for replanting in new locations on Fort McCoy’s 60,000 acres, much of which is naturally well-suited for wildlife habitat. No. 1 also collected, in a small plastic zip-lock sandwich bag, “waste” seeds when cleaning the drying racks. That handful of seeds were later sown on our property.
Lupines are now standard-bearers for the land we call home – leading the way for the wild flower pack on our prairie grass field in late May and early June each year. Their colorful blue flowers rise on tapered spikes and shout out loudly against last year’s dead grasses long before the greens of summer grasses take over the landscape.
Elsewhere, flowering lupines create seas of blue on large expanses of oak savannahs. Here, our small patch creates a lesser pond of blue; visible from the kitchen window, 200 yards away.
Wild lupine seeds, sown a decade ago have thrived on the spoils of Vera’s Pond – bulldozed in the ‘80s by neighbor Cliff. Lupine plants thrive best on power line rights-of-ways and utility corridors, military installations, forest trails and other open areas that are maintained as early successional landscapes like savanna and barrens communities. Without disturbance, natural or artificial, trees and shrubs take over and shade out lupine plants.
Wild lupine is unique as it’s the only plant that acts as the larval host for the endangered Karner blue butterfly. In mid-April, the plant sprouts from root systems and forms clumps of flowering stalks.
Two generations of Karner blue butterflies hatch each year. The first in mid-April from eggs laid the previous summer. Larvae creep up the stems to feed on new leaves. Peak bloom is reached by late May – the same time the first brood larvae pupate. Adults begin flying in late May through early June.
Aldo Leopold, in his now classic A Sand County Almanac, wrote: “Sometimes in June, when I see unearned dividends of dew hung on every lupine, I have doubts about the real poverty of sands. On solvent farmlands lupines do not even grow, much less collect a daily rainbow of jewels. If they did, the weed-control officer, who seldom sees a dewy dawn, would doubtless insist that they be cut. Do economists know about lupines?”
The trail that borders our pond cuts a path through the lupine. I paused the other day and looked for lupine dew, Karner blue larvae and flying adults. Butterflies of other stripes and several types of bees enjoyed the nectar and dew, but Karners, if they existed, were keeping to themselves.
But then again, there’s time. Active periods for both plant and butterfly last until mid-August. Plenty of time for you and I to take a peek while out for a walk or driving down our favorite country roads.