Delicate and tiny Karner Blues may face extinction due to their fussy appetites. The endangered butterflies deign only to dine on wild lupine.
The local species may vanish "even though we're doing everything we can to save it," says Jim Louderman, collections assistant in the Division of Insects at the Field Museum.
Louderman, who lives in Miller, often hikes the Indiana Dunes National Lakeshore where thousands of Karner Blues flit from the oak savannah to the wild lupines to lay their eggs. Karner larvae love that lupine nectar, too.
But not all lupines are equal. Not to the fussy Karner Blue.
"Karner Blues need to feed on wild lupine, not the ones we plant," says Chris Nyberg, executive director for Northern Indiana Citizens Helping Ecosystems Survive (NICHES).
Oh, yes, adults like lupine in the sun for feeding, and lupine in the shade for egg-laying. "Otherwise it doesn't produce the necessary chemicals for the caterpillar larvae in the winter," he says.
What's a pretty blue butterfly to do?
Protecting them from collectors who work to make butterflies extinct in order to drive up prices is one aspect.
"If you see a Karner Blue, call the Lakeshore," suggests environmental consultant James Bess, owner of Otis Enterprises, who is knowledgeable about Karner Blues.
Bess says that at one time Karner Blues -- also found in Michigan, Wisconsin and on the East Coast -- were extremely common.
"There were bands of them from New York to southwest Wisconsin," he says. "I remember in the 1980s when I was in high school, I would walk in the woods which would be blue from all of the butterflies."
That was then.
Now their habitats are fragmented. The butterflies are weak fliers, too, with a range of only about one half-mile. It's hard for them to move in and forage for fresh lupine.
"So for genetic exchange, in order to survive, they have to have lupines every one-half mile," Nyberg said. The species' fragile existence is tied to its habitat.
According to Kelly Cadell, interpreter park guide for the Indiana Dunes National Lakeshore, mid-July is a good time to try to spot Karner Blues. The rare beauties live in the lupine-friendly inland marsh and West Beach areas of the lakeshore. At this time of year, the second brood of the season are transforming from caterpillars to butterflies.
If you spot a Karner Blue, you are lucky. One, they are small butterflies -- their wing span is about an inch. Two, they only live for about a week or two. To complicate matters, they resemble the common Eastern Tail Blue butterfly.
"The distinctive feature of the Karner Blue is the band of orange spots under the wings," says Bess. "The Eastern has just one orange spot and a tail."
For those who like a little spice, the Karner Blue was first identified by author Vladimir Nabokov, famous for his racy book "Lolita." The writer-lepidopterist discovered the butterfly in Karner, N.Y., in 1862.
