The thinness of beech bark makes it vulnerable to a range of scale insects. Beech bark disease (BBD) is a scale-fungal complex disease, initiated when a specific scale insect, Cryptococcus fagisuga Lind., attacks the bark of beech trees and renders it susceptible to bark canker fungi of the genus Neonectria . Neonectria (Neonectria faginata or Neonectria ditissima) is the most common genus of ascomycete fungi associated with beech bark disease [6–8]. The disease develops through feeding activity of the beech scale insect that creates points of entryway for the fungal pathogen. Once established on the tree, the fungus is no longer influenced by fluctuations in beech scale density caused by environmental factors or habitat quality . The cankering response of beech to fungal infection produces bark microstructure fissures and when it progresses the cankers may coalesce girdling or partially girdling the tree leading to wilting foliage and even mortality of trees. Individuals that survive infection are more susceptible to abiotic and biotic stress .