As far back as 20 years ago, logger Robert Lehning would see a Volkswagen parked on a dirt roads near his company, Trees Unlimited.
The VW’s driver, lepidopterist David Norris, would assure Lehning he was harmless.
“He’d say, `It’s just me, walking around, looking for butterflies,’ ” Lehning said.
What Norris, a noted Connecticut entomologist, had found was something rare — one of the very few places In Connecticut where a small, beautiful butterfly, the northern metalmark, calls home.
“Why would I mind what he was doing?” Lehning said. “I thought it was interesting.”
Today, if anything, the butterfly is even more threatened across its range from Oklahoma to Virginia, north to a thin slice of western Connecticut, where it’s listed as an endangered species.
“It is very rare,” said Laura Saucier, a environmental technician at the state Department of Environmental Protection. “Connecticut has three sites where it can be found and maybe a dozen butterflies.”
That is why the DEP staff volunteered for a Day of Services in Bethel last week to mark the 10th anniversary of the federally funded State Wildlife Grants Program — a program that’s provided states with $573 million for wildlife projects.
The DEP work in Bethel has created a uncrowded woodland that lets in enough sun to help wildflowers grow. It’s also cleared away the invasive stands of autumn olive and oriental bittersweet that were crowding out native plants.
“Northern metalmarks like glades,” Saucier said. “They like dappled sunlight with herbaceous plants and wildflowers.”
After three years of clearing away brush, the wildflowers — and the metalmark — have returned.
“We found red columbine growing here this year,” she said. “It was beautiful.
“There was a real seedbank in the soil there,” said David Wagner, a professor of ecology and evolutionary biology at the University of Connecticut and one of the state’s best-known lepidopterists. “We were floored by the number of plants that came out.”
Northern metalmarks are small orange-brown butterflies, banded with an orange border.
“They’re little gems,” said Victor DeMasi, of Redding, a butterfly expert who has been observing the metalmarks in Bethel for about a decade.
The butterflies need a specific plant — roundleaf ragwort — as a host. It’s where they lay their eggs. The small white caterpillars that grow into northern metalmarks then feed on the plant.
Once hatched, the butterflies spend the summer feeding on wildflower nectar.
“They love butterfly bush and black-eyed Susans,” Wagner said.
In Connecticut the three spots where they’re found are in the Marble Valley — the marble- and- limestone formation that runs roughly from Ridgefield north along the Housatonic River to Massachusetts.
One spot is in Bethel, another at Bull’s Bridge Gorge in New Milford, and the third near a limestone quarry in Falls Village.
There are several things working against the metalmark. One is that as the state’s forests mature the canopy shades out wildflowers, which need sunlight.
Invasive species are pushing out native plants. The too-large herd of white-tailed deer in the state browse down wildflowers.
“And development can be an issue,” Wagner said. “The population density in places like Bethel is pretty high.”
That is why, whenever a few northern metalmarks showed up at Bethel site this year, it was a cause to cheer — for the butterfly and the habitat it needs.
“This is part of our heritage,” DeMasi said. “Just as the old homes in our towns make them look New England-y, these places are part of our natural heritage.”