Tent Caterpillar treatment and prevention

Asked August 27, 2018, 2:39 PM EDT

I have recurring tent caterpillar infestation in 5 Birch trees up to 40 ft height. Who can I discuss best management with? What prevention and treatment methods are recommended, especially for problems at these heights.

Clatsop County Oregon trees and shrubs fall webworm horticulture

1 Response

Fall webworms show up in late summer in the Pacific Northwest. They weave a web around themselves and the tree branch on which they dine. They rarely cause significant damage but are considered unsightly.

If possible remove the branch containing the nest and place it in a container of soapy water. You may also apply a biological control, Bt, to the nests. Due to the height of your trees, if you decide to remove the nests, consult a professional arborist who has the equipment to do so safely.

These webworms overwinter as pupae in a brown cocoon in protected places, such as in bark crevices or on the ground in litter or duff. By keeping the ground beneath your trees free of litter during the winter you can reduce the chances of infestation next summer.