The hairs break off in skin and cause an itchy rash in people who react to them. It does not sting in the way a puss caterpillar does, but it is worth not handling — especially for children, who pick it up because it looks soft.
We identify, we don't diagnose. If you've been bitten or stung and symptoms develop, or you're worried, seek medical attention.
Size35–45 mm long
MarkingsWhite and fuzzy with black tufts along the back · Long black hair pencils at the front and rear
WhereEastern North America, on deciduous trees and often found on the ground below them.
SeasonLate summer and autumn
What it is not
A hickory tussock moth is most often confused with a species that is medically significant. If you are trying to rule those out, check these:
Eastern North America, from the Carolinas north into Canada and west to the Great Lakes. It is often abundant in late summer.
Eastern North America, on deciduous trees and often found on the ground below them.
Late summer and autumn.
How it behaves
It feeds on hickory, walnut, ash, oak and other hardwoods, then leaves the tree to find somewhere to pupate — which is why they are so often found walking across the ground and on garden furniture in late summer. Numbers swing dramatically from year to year, and in a heavy year they can seem to be everywhere at once.
What a bite looks like
An itchy red rash where the hairs contacted skin, sometimes with small raised bumps. Reactions vary a lot between people; many feel nothing at all.
Itching and mild stinging rather than sharp pain. It usually settles within a day.
We identify, we don't diagnose. Lift the hairs out with adhesive tape and wash the area. See a doctor if the rash is severe or widespread, or if hairs get into eyes.
A skin mark cannot confirm which animal caused it. Read the bug bite and sting guide for the limits and the symptoms that should end an online search.
You’ve found one indoors
Tell children not to pick it up — it looks soft and that is exactly the problem. If one is on a play area or a handrail, brush it off with a stick rather than a hand, and wash hands afterwards.
Common questions
Is the hickory tussock caterpillar dangerous?
Not dangerous, but worth avoiding. The hairs break off in skin and cause an itchy rash in people who react to them. Many people handle them with no effect at all, which is part of why they get picked up.
What do I do if my child touched one?
Use adhesive tape to lift out the hairs, wash the area with soap and water, and use a cold compress for the itching. Seek medical advice if the reaction is strong or hairs have got near the eyes.
Why are there so many this year?
Populations are naturally cyclical and swing hard from year to year. A heavy year is normal and is usually followed by much quieter ones.
Leah Fulton · CC-BY