A quarter-sized butterfly with blue-and-purple wings and rarely seen along Colorado’s Front Range is a mystery to researchers who only know that it loves hops even more than the state’s legions of beer geeks.

Colorado Natural Heritage Program zoologists realized they could use that information to tap into the region’s obsession with all things craft beer-related to generate funding for more studies into the blue hops butterfly.

“It’s difficult to find a species or a habitat that appeals to a broader audience outside the conservation management community,” zoologist Robert Schorr said. “A butterfly that is rare and likes hops doesn’t present itself every day.”

The small butterfly, whose formal name is Celastrina humulus, lives along the Front Range between

El Paso County and the Wyoming border. It emerges only in June and July.

The insect is rare enough that a 1994 inventory of flora and fauna at the U.S. Air Force Academy noted only two sightings. But Schorr saw a cluster of 12 during a recent survey on academy property, prompting him to wonder more about where they are, how rare are they, when they emerge and why they like hops so much.

Schorr presented his interest in the butterfly to Odell Brewing Co. in Fort Collins.

“All of us immediately were completely intrigued and compelled by the story,” Odell marketing manager Amanda Johnson-King said. “It is such a fun story. The big piece is that it is this little creature that lives on hops, and that is such a part of our industry.”

Hops are a main ingredient in beer, providing bitterness and tang.

On May 18, Odell Brewing will make a limited release of Celastrina Saison, a French-style beer. For every bottle sold, the brewery will donate $1 to the Colorado Natural Heritage Program at Colorado State University’s Warner College of Natural Resources.

About 10,000 bottles are expected to be produced. Even a donation of $5,000 would help get researchers into the field to study this butterfly, program director David Anderson said.

“This is where conservation needs to go,” he said. “Here we have something that is so remarkable in Colorado that lives on hops. And beer is such a remarkable part of Colorado’s culture that it fits so nicely.”

Last year, Pateros Creek Brewing Co. in Fort Collins brewed Spiranthes Extra Pale Ale in recognition of a northern Colorado wildflower. Proceeds supported the Colorado Rare Plant Initiative.

Craft breweries throughout the country are becoming major fundraisers. Samuel Adams Brewery last month

said it will donate profits from a limited-edition beer to victims of the Boston Marathon bombing.

“This is just another example that small and independent craft brewers are using their breweries and businesses as a cause for other causes,” said Julia Herz of the Boulder-based Brewers Association.

Odell Brewing founder Doug Odell said the collaboration seemed to be a natural fit for his brewery — helping out a study that involved Colorado wild hops, even though they aren’t suitable for brewing. “Too many off flavors,” he said.

Celastrina Saison, which will be released first in Odell’s taproom and then in bomber-style bottles in 10 states, is a fruity blend.

Odell called it a marriage of a lot of flavors — like the marriage of beer, butterflies and conservation funding.

Jeremy P. Meyer: 303-954-1367, jpmeyer@denverpost.com or twitter.com/jpmeyerdpost