Rare 'elfin' butterfly species found in western Massachusetts

MONTAGUE - Massachusetts wildlife experts are celebrating the return of a rare species of butterfly.

MassWildlife staff recently discovered a frosted elfin caterpillar in the Montague Plains Wildlife Management Area, the agency said. They were only known to be in about two dozen sites in the state and this one was spotted a mile from one of them, which is notable because they rarely leave the habitat in which they grew up.  

The species' numbers have been dwindling because its favorite flowers were disappearing - they only lay eggs on two types of plants that grow in the area. Caretakers in western Mass. have been regrowing the habitat for the past 20 years. 

"It is incredibly rewarding to see decades of effort paying off to benefit this threatened butterfly," Habitat Program Manager Brian Hawthorne said.