Hickory Tussock Moth Caterpillars

Hickory Tussock Moth caterpillar

The Hickory Tussock Moth Caterpillar is white and fluffy and has black chain-like markings on its back. It also has long black hairs that stick out from areas near the front and back of the caterpillar.1 It grows to a length of about 4.5 centimeters.1 The Hickory Tussock Moth Caterpillar can be found in Southern Ontario from July to September, at which time it feeds on the leaves of hickory, walnut, ash, elm and oak trees in preparation for overwintering in its cocoon.1

Why should I be concerned about Hickory Tussock Moth Caterpillars?

Touching these caterpillars can cause a rash similar to that caused by nettles or poison ivy. Symptoms can range from slight reddening of the skin to a burning sensation with swelling and pain.2 Some people may experience a headache, nausea or an allergic reaction.2

What should I do if I have touched one of these caterpillars?

If you touch a Hickory Tussock Moth Caterpillar, it is recommended to wash the affected area with soap and water as soon as possible. In the case of itching or swelling, apply calamine lotion and/or ice packs to the affected areas.2 Individuals who experience more generalized allergic reactions should seek medical advice from a doctor.

Some people experience pain after touching these caterpillars, however this is not a sign of disease. It is just the caterpillar’s natural defenses, a way of protecting itself. Because of this, the Huron County Health Unit does not track or test the caterpillar.


1Wagner, D.L. (2005). Caterpillars of eastern North America: A guide to identification and natural history. New Jersey: Princeton University Press.

2Goddard, J. (2007). Physician’s guide to arthropods of medical importance. (5th ed.). Boca Raton: CRC Press, Taylor & Francis Group.

Adapted with permission from the Middlesex London Health Unit.


If you have a question please call us at 519.482.3416 or toll-free at 1.877.837.6143. Ask to speak to a public health inspector on the Environmental Health team.