Tussock Moths

Tussock moth is a general feeder of conifers and deciduous trees. Outbreaks of the moth appear to develop rapidly and then usually subside abruptly after a year or two. Defoliation by the tussock moth kills many trees, weakens additional trees that are eventually killed by bark beetles, and retards tree growth for several years.

Usually the first indication of attack appears in late spring. Larvae from newly hatched eggs feed on current year’s foliage, causing it to shrivel and turn brown. Defoliation occurs first in the tops of trees and the outermost portions of the branches, and then in the lower crown and farther back on the branches.

Many times, natural enemies such as small wasps and some birds kill these moths, but if they are not removed by natural environmental controls, other means must be used. Monitoring and prevention are most important. Application of natural and synthetic controls are available for control of Tussock Moth. Applications are most effective while caterpillars are in the young stage.

Please call or email City Arborist Tree Care to discuss your tree’s disease and pest control needs.