A seven-inch green caterpillar with long, black horns moved slowly from twig to twig, taking small bites from the leaves brushing against its head. The lanky larva provoked mixed reactions from the 6-year-old watching with wide eyes.
“It’s really cool,” Anthony Burrell exclaimed.
“Ew,” he added a moment later.
Anthony was one of the many children who were fascinated by the array of live caterpillars and moths displayed at the Petersham Memorial Library on Wednesday. It was one of many stops for the Caterpillar Lab, a traveling, educational exhibit.
Dozens of caterpillars — from species like the hickory horned devil that entranced Anthony, to the banded woolly bears familiar to New England gardeners, to the camouflaged four-horned sphinx — were allowed to climb potted plants and eat freely while families got a close look.
In a few cases, the fully matured moth counterpart to a certain caterpillar was also available in a cage for examination, like the bright orange moth the green hickory horned devil becomes.
The hickory horned devil was a favorite to many who walked through, as it wasn’t quite as common a sight like some of the others.
According to Gemma Laser, a graduate student at Antioch University New England in Keene, N.H. who helped run the event, the hickory horned devil — also known as the regal moth or royal walnut moth — was once common in New England, but became less and less common during the latter half of the 20th century, and is now only found as far north as New Jersey.
“They really are native to here but have been pushed south,” Laser said. “This is the longest caterpillar in the world, and it was right here.”
Unlike the hickory horned devil, many large caterpillars and moths can still be found throughout New England, right in people’s backyards, Laser said.
For example, the polyphemus moth, which turns from a plump green caterpillar into a large brown moth with purple markings — “eyes” — on its wings, and even the yellow imperial moth may be found in Massachusetts.
“The whole point of this lab is environmental education,” Laser said. “All of this is not in the Amazon. It’s right here in New England.”
Jimmy Burrell, who brought his son and nephew to the exhibit, didn’t realize the breadth of caterpillar species found in New England and said he would be looking more closely for colorful or particularly large caterpillars during his next walk in the woods.
“You don’t always know this type of thing is in your backyard,” Burrell said. “Plus, when you think of everything being connected, I’m a farmer and a naturalist, and it’s important to learn about our ecosystem. This is what feeds the birds.”
According to Laser, one of the purposes of the Caterpillar Lab as a nonprofit is to peak people’s interests in the local ecosystem. The organization, based in New Hampshire, doesn’t do research, but travels throughout New England to different libraries and schools to host its caterpillar exhibits.
“On one level, what amazing creatures,” Laser said. “They have personalities. There are the more gregarious caterpillars, then there are the independent caterpillars. They are all different.
“We have this amazing wealth and the earth is where you find it,” she added. “It’s grounding for people, seeing this one part of their ecosystem. It’s also unusual. It’s something people normally don’t come and see.”