Bulletin E2299
Comparison of the Eastern Tent Caterpillar, Forest Tent Caterpillar, and Gypsy Moth


May 1, 2001 - <mccullo6@msu.edu>

Note: The Governing Board of the Entomological Society of America elected to change gypsy moth to spongy moth in early 2022. The transition to the new common name will likely be a multi-year process. To maintain consistency for those who have been dealing with this pest, several of our outreach materials may include the previous common name, gypsy moth.

These three insects are often found feeding on the leaves of hardwood trees easily confused with one another. The illustrations and information here will help you to identify which caterpillar is feeding on your trees. Contact your local MSU Extension office or regional Dept. of Natural Resources office for more information on the biology and management of these insects.






Eastern Tent Caterpillar (Malacosoma americanum)

Forest Tent Caterpillar (Malacosoma disstria)

Gypsy Moth Caterpillar (Lymantria dispar)


A) Dark head B) Prominent white or yellow stripe down the center of the body; C) small blue spots to the side.

A) Blue head; B) Prominent central row of white or yellow markings in keyhole or footprint shape; C) Bluish on sides of body.

A) Yellow head with black markings; B) Prominent blue and red spots.


Prominent silk tent in branch junction.

They do not spin silk tents; resting sites on leaves may have small silk layer.

No silk tents

Egg Mass

Dark, spindle-shaped mass wrapped around twigs; rough varnished texture.

Similar to eastern tent caterpillar.

Tan color; covered with fine hairs; 1 to 3 inches long; usually on tree bark

Preferred Host Trees

Black cherry, apple, crabapple.

Aspen, sugar maple, oaks, birch, black gum.

Oaks, aspens, birch, willow and more than 250 other species.


Native insect; silk tent is unattractive, but feeding rarely harms trees; common pest of ornamental trees in urban settings

Native insect; outbreaks occur at roughly 10-year intervals and usually last 2 to 4 years; most common in forests, especially where aspen is abundant.

Exotic pest; severe defoliation during outbreaks can occur for 2 to 3 years in urban and forested areas, especially where oaks are abundant.



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