European gypsy moth (lymantria dispar L.) outbreaks: a review of the literature

The literature on tree mortality following outbreaks of European gypsy moth was reviewed. The trends in defoliation and mortality and the influence of defoliation on mortality of individual trees and forest stands have been summarized via a regional perspective. The literature showed that: certain tree species are defoliated at higher rates than other species, and frequently suffer greater mortality than less susceptible species; as the intensity (amount of foliage removed) and duration (number of consecutive episodes) of defoliation increases, the amount of tree mortality increases; trees in the lower canopy (those in the suppressed and intermediate crown classes ) have a greater probability of being defoliated and dying than trees in the upper canopy (dominants and codominants); and tree mortality tends to increase rapidly during the second year after defoliation.