How to Manage Pests

Pests in Gardens and Landscapes

Foliage-feeding caterpillars

Caterpillars are the larval stage of moths or butterflies. Many species feed in leaves of trees. Larvae have three pairs of legs on the area immediately behind the head and leglike appendages on at least some segments of the abdomen but not on the first two.

Identification of species | Life cycle


Some caterpillars fold or roll leaves together with silk to form shelters. Others feed on leaves beneath a canopy of silk, sometimes creating "nests" in foliage, and others devour entire leaves along with stems. Severe defoliation may cause branch dieback or kill entire plants.


Clip and dispose of infested foliage. Inspect the bark and scrape any egg masses into a bucket of soapy water and dispose of them. Provide proper fertilization and water, protect roots and trunks from damage, and prune trees properly when needed. General predators, parasites, or naturally occurring viruses may help keep populations under control. Applications of Bacillus thuringiensis applied when larvae are newly hatched will reduce populations of caterpillars that feed openly on foliage.

For more information on leafrollers, see the Leafrollers on Ornamental and Fruit Trees Pest Note.

Fruittree leafroller and foliage tied together
Fruittree leafroller and foliage tied together
Fall webworms and chewing damage
Fall webworm and chewing damage
Cotoneaster webworm
Cotoneaster webworm

Statewide IPM Program, Agriculture and Natural Resources, University of California
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