Fig. 3.

Effect of damage by three herbivore species on the concentrations of two defense hormones, salicylic acid and jasmonic acid, in the damaged and adjacent undamaged leaves of young Populus nigra trees as compared to equivalent leaves from non-infested control trees. Samples were collected 44 hr after infestation with caterpillars of Amata mogadorensis and Lymantria dispar, and adults of the beetle Phratora vulgatissima, and from undamaged control plants. The boxplots depict medians ±1.5 x interquartile range of n = 10 tree replicates. Pairwise comparisons were conducted using Tukey’s post hoc test (ANOVA) and Dunn’s post hoc test (Kruskal-Wallis) and are indicated by small letters. Circles indicate outliers. Statistical results comparing only the herbivore treatments are given in Table 1