The white, fuzzy caterpillar crawled along Jace Porter’s hand until it settled on the perch of his thumb.
Porter, who works at The Caterpillar Lab in Keene, found the caterpillar Thursday in a bucket filled with a sumac branch that had recently been collected to help feed the hundreds of insects at the facility.
The hairy white caterpillar with black spots down its back belongs to a species known as the hickory tussock moth caterpillar. The hickory tussock, which is commonly seen in New Hampshire at the end of summer and early fall — four to five weeks after it has hatched from an egg and grown to its full size — has a somewhat unfair reputation, according to Porter.
“This particular caterpillar tends to get a bad rap,” he said.
This stems from irritants on the caterpillar’s white hairs which, in rare cases, cause allergic reactions when they come in contact with human skin.
Sometimes, people who touch the caterpillars develop slight redness on their skin and, less frequently, an itchy, burning rash, Porter said.
In the past month, hickory tussocks have been visible throughout the Monadnock Region, and this year, they seem to be coming out in great numbers. Populations of these caterpillars fluctuate from year to year, depending on the success of their predators, which include birds, wasps, flies and reptiles.
Sam Jaffe, the executive director of The Caterpillar Lab, a nonprofit organization that teaches natural history through caterpillars, puts lights outside his Marlborough home to attract moths each year. This summer, he said he’s seen a great number of hickory tussock moths, which are also known as tiger moths because of their orange color and white spots. These moths lay eggs in “large masses” over the summer; in turn, those eggs hatch into hickory tussock moth caterpillars.
“This year, it just seems like they’ve done very, very well,” Jaffe said of the hickory tussocks.
Every year, The Caterpillar Lab is “inundated” with questions about these white caterpillars because of their reputation for causing allergic reactions, according to Jaffe.
But he and Porter say this reputation is blown out of proportion. So does David Wagner, an entomologist at the University of Connecticut. Wagner estimates that only about one out of 100 people will experience allergic reactions.
“You’d have to have extremely sensitive skin,” he said, noting that he’s never met anyone who’s had a reaction after touching a hickory tussock.
Yet stories that characterize the caterpillar as a very dangerous insect abound on the Internet and across social media platforms.
“What we see a lot in these articles are very sort of alarmist tones, things that describe these as sort of evil, invading creatures and that make it seem they’re sort of out to get us,” Jaffe said.
An article on boredomtherapy.com describes the hickory tussocks: “It’s important to remember that as painful as this caterpillar’s venom may be, it’s not fatal. Nonetheless, the subsequent stinging and rash is a surprise coming from something so cute and fuzzy. Warn everyone you know about the danger of touching this little guy.”
An article published on goodhousekeeping.com in 2015 strikes a similar tone.
“If you think letting your kids catch caterpillars is as innocent an autumn activity as jumping in leaves or picking pumpkins, you might want to think again.”
Still, Jaffe said he doesn’t encourage children and parents to pick up hickory tussocks directly with their hands, in the rare event that children do experience an allergic reaction.
But he doesn’t think people should fear the insects. He encourages kids and parents to interact with the caterpillars by picking them up with sticks, or even rearing them at home in small cages.
But he hears many stories of people reacting in the opposite way.
“I see missed opportunities when we hear the fear mongering and when we hear of people just squishing them,” Jaffe said.
There are several species of caterpillar in New Hampshire that can pack a greater punch than the hickory tussock. The io moth caterpillar, for example, can cause a painful sting due to the clusters of venomous spines along its back. Flannel moth caterpillars, which are found more commonly in the Seacoast region, also have venomous spines.
There are also several other species of white, hairy caterpillars that look like the hickory tussock. Some of them have irritant residue on their hairs; others do not and simply mimic the bright white appearance to ward off predators.
In the coming weeks, hickory tussock caterpillars will be forming cocoons. Over the winter, they will develop as pupae until they emerge from the cocoons as moths in the spring.
Porter and Jaffe say it’s important for people to see past the caterpillar’s reputation. The hickory tussock evolved in the Northeast over thousands of years and plays a crucial role in the food chain, according to Porter.
“These are totally native ... they feed birds, they keep plants in check, they feed other insects,” he said. “They’re just an important part of our local ecosystem.”