Gora, V., König, J., & Lunderstädt, V.J. 1996 Population dynamics of beech scale (Cryptococcus fagisuga) (Coccina, Pseudococcidae) related to physiological defence reactions of attacked beech trees (Fagus sylvatica).. Chemoecology 7: 112-120.

Notes: Changes in the density of beech scale infestation (Cryptococcus fagisuga) of a mature beech stand (Fagus sylvatica) were investigated after gap-cutting in limed and unlimed areas bordering on the gaps and in untreated areas over a 5-year period. Concentrations of sucrose, protein amino acids, and procyanidins were also examined in the inner and outer bark of non-infested beech trees and beeches infested by beech scale. Procyanidin content increased, protein amino acid content decreased and a change in the outer bark-inner bark-ratio of the infested trees showed a transfer of compounds between inner and outer bark. Long lasting shifts occurred in the pattern of compounds of the bark irrespective of actual infestation intensity.