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Hickory Tussock Moth caterpillar

Have you seen this caterpillar? If you spot one, don't touch it.

What is a Hickory Tussock Moth caterpillar?
The caterpillar is white and fluffy and has black chain-like markings on its back. It also has long black hairs that protrude from areas near the front and rear of the caterpillar; these hairs are connected to poison glands which excrete venom on contact.

What happens after you touch a Hickory Tussock Moth caterpillar?
The caterpillar can leave behind venom that 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. Some people may experience an allergic reaction which could include nausea.

What to do if you’ve been in contact with a Hickory Tussock Moth caterpillar
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 affected areas. Individuals who experience more generalized allergic reactions should seek medical advice from their family physician.

The Hickory Tussock Moth caterpillar is present 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. The caterpillars grow to a length of about 4.5 centimeters.

Adapted with permission from the Middlesex-London Health Unit.