White fuzzy caterpillar not fluffy, but also not fatal

Photo by Yelena Kisler – Pictured is the white hickory tussock moth caterpillar, which while not poisonous, can cause irritation from its tiny barbed hairs, especially in children, whose skin tend to be more sensitive than adults. They are non invasive, and native to our area
Yelena Kisler
Staff Writer

Native to our area, the white hickory tussock moth caterpillar can be found all over. And while many of us may not know much about this fluffy-looking caterpillar, it's been getting a reputation online for being poisonous when, in fact, it's not.
The hickory tussock moth (Lophocampa caryae), is a type of tiger moth that is a member of the Erebidae family of Lepidoptera, and are widespread throughout the northeastern and north central U.S., and parts of Canada.
"They're reasonably common to very common [in this area], they feed on a variety of hardwood trees, and they're native here, so it's not like they're invasive or anything," said Michael Skvarla, Ph.D., insect identifier and Extension educator at PSU. "They come out in the fall, primarily, and over-winter as a cocoon."
Recently, a number of articles have popped up online claiming that these caterpillars are toxic and potentially deadly, but Skvarla says that's simply incorrect.
"There are a handful of case studies of children, particularly toddlers, eating either the caterpillars or the cocoons. The cocoons are problematic because they incorporate the hairs into the cocoon and when that happens, it can be an issue," said Skvarla. "Their throats itch and there might be some swelling, but in every case, with supportive care, it goes away in a couple of days as the hairs dislodge themselves from the throat and the tongue. There's not been a fatal case reported in humans."
He added that he doesn't know of any documented cases of death in pets from the caterpillar either.
"Touching it is pretty innocuous [for adults]," said Skvarla. "If you're careful, you could just pick the caterpillar up, some of the hairs will detach, but in an adult's fingers, it won't do much. If you rub your eyes after that and get the hairs in your eyes, that could be problematic."
The University of Maine notes on their website that some people can have a more severe rash as a reaction to the hairs than others. The website says "the rash can be much more severe and long-lasting, and a doctor’s visit might be warranted to speed one’s recovery and ease the symptoms / discomfort."
"They're not venomous like they don't have toxins in them. It's mostly that the hairs are irritating," said Skvarla. "They've got barbs that can stick into you."
It's those barbs that cause irritation and, possibly, a rash, and since they are so fine, it's possible to disperse them without realizing it.
"One of the problems with the cocoons, aside from the hairs, is they spin them in hidden areas, so they'll be under boards and behind stuff outside, and if you pick up a board without gloves on and accidentally crush a cocoon, you could crush it into your fingers and it will itch."
Skvarla said now is the time of year when they are most visible to us because they're in the late caterpillar stages and are larger.
"People see the mature caterpillars most often because they're big, and they'll see those in the fall," he said.
I do get reports about them earlier in the year in the early parts of summer because the caterpillars when they first hatch out feed gregariously, so they'll see a whole group of them on one leaf."
As far as being any danger to your garden or foliage, Skvarla explained that since they're not invasive, they're not considered a "pest" in this region.
"They eat a variety of hardwood trees, oaks primarily, but also hickory, maples, elms, and some other hardwoods," he said. "In really bad years, they can defoliate trees, but healthy trees can withstand one or two years of total defoliation with no long-term effects. Tussock moth caterpillars generally don't outbreak more than one year in a row, so while they can be problematic from an aesthetic point of view… but they generally don't cause long-term problems."
All in all, while the hickory tussock moth caterpillar can be dangerous to children and irritating to adults, they're not as scary as they seem.
"Don't eat them, or stick them in your eyes, but there are much much worse things out there than these guys," said Skvarla.


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