Adirondack Nature Detective: Eastern Tent Caterpillar or Gypsy Moth?

By Diane Chase

Did you know that Gypsy Moths were introduced in the United States as a failed attempt at creating a silk industry similar to the silkworm? The Gypsy moth was brought from Europe to Massachusetts in 1869 by Leopold Trouvelot in attempt to breed the moths for silk production. A few escaped and now the moths defoliate trees from east to west coasts of the United States.

Well, Mother Nature is trying to trip my apple growing by first giving that cute fawn apple leaves to nibble upon and now a bout with tent caterpillars.

So what is the difference between the Eastern Tent Caterpillar, Forest Tent Caterpillar and the Gypsy Moth? 


Eastern Ten Caterpillar "tent"
The Eastern Tent Caterpillar
• black heads, light brown body with hairs with a white stripe.
• Light stripe down its back bordered with brown and black wavy stripes on either side
 There are a series of blue and black dots along the length of the body
• Length - about 2 to 2 1/2 inches
• The moth is rust/reddish in color with white bands on the forewings
• Are native in the Eastern US, north of the Rockies
• Spin hideous cobwebby-type nests in the crooks of trees
egg sac for Eastern Tent Caterpillar
• Prefer black cherry trees, apple and other fruit shade trees
• The egg sac overwinters and has a varnished look and will appear on small branches.

WARNING: Do not attempt to burn tents out of trees. Not only does it damage the trees but may cause forest fires if not controlled.


Forest Tent Caterpillar
• A misnomer because they don't really form a tent like their cousin the eastern ten caterpillar
• Form cobbwebby nests at the trunks and branches of mostly hardwood trees like oak, sugar maple
• Caterpillars will have pale blue lines along the sides of a light brown body.
Forest Tent Caterpillar (USDA Forest Service)
• Keyhole shaped white spots down the middle of the back. Sparsely covered with whitish hairs, 
•About 2 inches in length.
• Adult moths are buff-brown, with darker oblique bands on the wings. 
• Look for egg masses to encircle twigs covered in a frothy, dark brown substance.

Photo of a Gypsy Moth caterpillarGypsy Moths
• The caterpillar has five pairs of blue spots followed by six pairs of red spots along its back
• Also look for a thin yellow stripe down its "back"
• White hairs complete the picture


Photo of an adult gypsy moth

© Diane Chase, author of Adirondack Family Time: Tri-Lakes and High Peaks (Your Four-Season Guide to Over 300 Activities) available online or bookstores/museums July 2011. Diane is currently working on the second guidebook in the four book series of Adirondack Family Activities.

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