Gypsy moth infestation in Populus tremuloides: the role of leaf palatability.

Abstract

An experiment was conducted to determine the role of leaf palatability with respect to variation in levels of gypsy moth infestation between clones of P. tremuloides in the Pellston Plain. The variation in the number of pupae observed per clonal genet between clones was found to be significant (X2=24.327, the critical value for nine degrees of freedom for p=0.01 is 21.666). Variation in tannin concentration as determined by taste was found to be significant between clones (X2=18.547, the critical value for nine degrees of freedom for p=0.05 is 16.919). Variation in the concentration of phenolic compounds as determined by taste was not found to be significant (X2=10.400, the critical value for nine degrees of freedom for p=0.05 is 16.919). The relationship between the concentration of tannins and phenolics to infestation levels could not be determined with confidence. There appeared to a slight positive correlation between chemical concentrations and infestation levels but large error bars based on the standard deviation of the data make this interpretation questionable.