How to Manage Pests

Pests in Gardens and Landscapes

Fall cankerworm—Alsophila pometaria

Cankerworm larvae have three pairs of prolegs. They are greenish above, with three narrow, whitish stripes and one yellow stripe along the side of the body; underparts are light green. Cankerworms frequently stand on the posterior pair of prolegs in such a way as to resemble a small twig.


Cankerworm larvae are primarily leaf feeders, tending to skeletonize leaves. Occasionally they feed on young fruit by biting deep holes, which later heal, but leave large scarred depressions similar to the injury caused by green fruitworms.


On small trees, cut out and destroy infested twigs. If populations are high, applications of Bacillus thuringiensis or spinosad may be helpful.

Fall cankerworm larva
Fall cankerworm larva

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