Michigan State University Extension

hese three insects are often found feeding on ing on your trees. Contact your local MSU the leaves of hardwood trees early in the Extension office or regional Dept. of Natural T summer. They can be easily confused with Resources office for more infonnation on the one another. The illustrations and information here biology and management of these insects. will help you to identify which caterpillar is feed-

JIllls/ratiolls1Jy Pela Cnrrillgloll

Eastern Tent Caterpillar Forest Tent Caterpillar Gypsy Moth Caterpillar (Mn!ncosolI/n nJllericnll1l1l1) (Mn!ncosolI/n disstrin) (LYlI/nl1trin dispnr)

Markings A) Dark head; B) promi­ A) Blue head; B) prominent A) Yellow head with black nent white or yellow stripe central row of white or yel­ markings; B) prominent down the center of the low markings in keyhole or blue and red spots. body; C) small blue spots footprint shape; C) bluish to the side. on sides of body.

They do not spin silk tents; Tents Prominent silk tent in No silk tents. branch jW1Ction. resting sites on leaves may

have small silk layer. (Over) Eastern Tent Caterpillar Forest Tent Caterpillar Gypsy Moth Caterpillar (MnlncosolJln nl11ericnJllllJI) (MnlncosolJln disstrin) (LYlJlnl/trin dispnr)

Egg Mass Dark, spindle­ Similar to Tan color; shaped mass eastern tent covered wrapped around caterpillar. with fine twigs; rough var­ hairs; 1 to 3 rushed texture. inches long; usually on tree bark.

Preferred Host Trees Black cherry, apple, Aspen, sugar maple, oaks, Oaks, aspen, birch, willow crabapple. birch, black gum. and more than 250 other species.

Native insect; silk tent is Native insect; outbreaks Exotic pest; severe Populations lmath-active, but feeding occur at roughly la-year defoliation during out­ ral"ely harms trees; com­ intervals and usually last breaks can occur for 2 to 3 mon pest of ornamental 2 to 4 years; most common years in urban and trees in urban settings. in forests, especially where forested areas, especially aspen is ablmdant. where oaks are abwLdant.

MSU is an affirmative-action equal-opportunity institution. Michigan State University Extension programs and materials are open to all without regard to race, color, MICHIGAN STATE national origin, gender, religion, age, disability, political beliefs, sexual orientation, marital status, or family status.• Issued in furtherance of Extension work in agri­ UNIVERSITY culture and home economics, acts of May 8 and June 3D, 1914, in cooperation with the U.S. Department of Agriculture. Margaret A. Bethel, acting Ex1ension direc­ tor, Michigan State University, E. Lansing, MI 48824.• This information is for educational purposes only. References to commercial products or trade names do not imply endorsement by MSU Extension or bias against those not mentioned. This bulletin becomes public property upon publication and may be printed verbatim EXTENSION with credit to MSU. Reprinting cannot be used to endorse or advertise a commercial product or company.

Revised 4:01 - 10M - KMF - JP - Price: 25C, single copy free to Michigan residents. File 27.35 (Pests and Pest Management)