The hickory tussock moth is a common species in the northeastern United States and southeastern Canada, best known for its striking white and black caterpillar that can cause skin irritation on contact. If you’ve spotted one of these fuzzy caterpillars on a tree, a deck railing, or crawling across a sidewalk in late summer, here’s what you need to know.
How to Identify the Caterpillar
Young hickory tussock moth caterpillars are white with black spots. As they mature, they grow up to about 1.7 inches (4.5 cm) long and become covered in dense white hairs with distinct black tufts arranged in a row along the back. A pair of longer black hair “pencils” typically extends from the front and rear ends. The overall look is unmistakable: a fuzzy white caterpillar with bold black accents, almost like it’s decorated.
The adult moth is far less conspicuous. It’s tan to light brown with rows of cream-colored spots on its forewings and pale cream underwings. Adults are active in early summer and are drawn to lights at night, but most people never notice them. It’s almost always the caterpillar that catches attention.
Where and When You’ll Find Them
Hickory tussock moths are historically common across the northeastern United States and the adjoining Canadian provinces, including Ontario and Quebec. They produce one generation per year. Adults emerge in June, and eggs can hatch within the same month after an incubation period of about 15 to 16 days. The larval (caterpillar) stage lasts roughly 87 days, though this varies considerably.
Mature caterpillars are most visible from July through September, and it’s not unusual to spot them wandering through yards and managed landscapes well into the fall. They feed on a wide range of hardwood trees, with hickory, walnut, ash, elm, and oak among the most common hosts. In autumn, the caterpillars pupate, and the pupa overwinters until the following June.
Are the Caterpillars Dangerous?
The white hairs look soft, but the black tufts contain barbed setae (tiny, stiff hairs) that can break off and embed in skin on contact. This triggers a reaction that ranges from mild to moderately uncomfortable. Most people experience something similar to a localized rash: small red bumps, itching, and mild swelling that can resolve within an hour or persist for several days. In more sensitive individuals, the reaction can include scaly patches, blistering, or a widespread eczema-like rash that lasts weeks.
Systemic reactions like nausea, abdominal pain, or dizziness are rare with this species. The hickory tussock moth is not in the same league as the puss caterpillar, which causes severe pain in everyone who touches it and triggers serious systemic symptoms in roughly one in three cases. Still, the hickory tussock is one of the more common causes of caterpillar-related skin irritation in the Northeast, simply because there are so many of them and they’re easy to encounter.
Children and pets are at higher risk because they’re more likely to pick one up. The caterpillar doesn’t sting or bite deliberately. The hairs detach passively, so even brushing against one on a leaf or railing can transfer them to your skin.
What to Do If You Touch One
If you or a child makes contact with a hickory tussock moth caterpillar, the first step is removing the embedded hairs. Press a strip of adhesive tape (packing tape or duct tape works well) firmly against the affected area, then peel it off. Repeat several times with fresh strips. This pulls out the tiny barbed setae that your fingers can’t grip. Avoid rubbing the area, which only pushes the hairs deeper into the skin and spreads them around.
After removing the hairs, wash the area gently with soap and water. An over-the-counter hydrocortisone cream can reduce itching and inflammation. Oral antihistamines help if the itching is widespread. If you develop blistering, a rash that keeps expanding, or any signs of a more serious allergic reaction like difficulty breathing, seek medical attention.
If hairs get into your eyes, flush them with water and avoid rubbing. Eye exposure is uncommon but can cause significant irritation and warrants a trip to a healthcare provider.
Managing Them on Your Property
Hickory tussock moth caterpillars feed in groups when young, which means you might find a cluster of them on a single branch. If you need to remove them, wear gloves and long sleeves. You can clip the branch and dispose of the caterpillars in a sealed bag, or knock them into a bucket of soapy water.
Healthy, mature trees tolerate the feeding damage well. These caterpillars rarely cause enough defoliation to threaten an established tree, especially since they feed late in the growing season when trees have already stored much of their energy for the year. Chemical treatment of trees is almost never necessary for this species. If you’re seeing heavy numbers on a young or stressed tree, a targeted application of a biological insecticide containing naturally occurring soil bacteria can reduce populations without harming other insects. Your local cooperative extension office can advise on whether treatment makes sense for your situation.
The simplest strategy is awareness. Teach children not to touch fuzzy caterpillars, check outdoor furniture and play equipment in late summer and early fall, and shake out towels or clothing that have been left outside. The caterpillars are harmless to look at. The only risk comes from direct contact with those deceptively soft-looking hairs.