Cute But Prickly: The Hickory Tussock Caterpillar

The hickory tussock moth larva, showing up now around East Lansing, may look rather Disneyesque in cuteness, what with their fuzzy white bodies and black spots.

But be aware the little critters come with prickly self-defense hairs that, according to Wikipedia, “cause itchy rashes (contact dermatitis) in many people, particularly those prone to allergies … and may cause serious medical complications if they are transferred from the hands to the eyes.”

East Lansing resident (and Council member) Ruth Beier photographed the caterpillar in question above, after finding more than a dozen on her deck.

She asked me to alert our neighborhood, the Oakwood Historic Neighborhood, via our email list, and I’m reporting this also to ELi readers because, as Beier pointed out, “They look all cuddly, and I am afraid that some unsuspecting science-type kids might try to hold them.”

An MSU Extension article by Gretchen Voyle from 2014 indicates that these caterpillars may show up on various types of trees found in Michigan, including hickories, walnuts, ash, elm, maples, and oaks.

Writes Voyle, “Picking it up with your hand would be less aggravating than dropping it down your shirt, although neither is recommended. Since there are Internet sites that are calling the larvae toxic or poisonous, this is not what it seems. The only danger is skin irritation or a rash.”

The Extension Service of the University of Maine gives a little more warning:

“When the caterpillars are ready to spin their cocoons in the fall, they spin them using the leaf litter and their own hairs (as other tiger moths do as well). Thus, their cocoons are also capable of causing a rash whenever people come into contact with them, so as the Maine Forest Service points out, use caution when raking leaves following a season when the caterpillar population has been high.”

Both extension services suggest that these caterpillars do not cause major problems for trees, so they should not be seen as a sign of imminent tree death.