Cotoneaster: Cotoneaster webworm

categories: Cotoneaster Cotoneaster Insects Ornamentals Shrubs

revision date: 2023-12-02 09:17

Cotoneaster webworm damage.
Cotoneaster webworm damage
Photo by: C.R. Foss


The cotoneaster webworm is a dark brown caterpillar, 1/4″ to 1/2″ long. It typically ties clumps of leaves together with webbing and feeds within the nests, skeletonizing leaves. The caterpillars feed during the summer and fall, overwintering in nests on the plant and pupating in the spring. The dark gray, night-flying adult moth emerges in the spring to lay eggs. The webworm is primarily a problem on Cotoneaster horizontalis (rock cotoneaster).

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

  • Hand-pick and kill caterpillars.
  • Prune out and destroy nests.
  • Remove any overwintering nests found on the plant.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • Monitor plants and apply product when caterpillars first appear.
  • Homeowners should not make foliar applications to trees over 10 ft tall.
  • Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.

Approved Pesticides

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

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