Fig. 2.

(A) Water contents and (B) hydrogen peroxide concentrations of P. sylvestris after exposure to sawfly sex pheromones and subsequent egg deposition. Measurements were conducted 12 d after pheromone exposure, that is, 11 d after egg deposition, at the end of the egg incubation period. Water concentrations and hydrogen peroxide concentrations were determined in pine needles from untreated trees, from trees exposed to the solvent hexane (without eggs: hexane control; with eggs: hexane + eggs), and from trees exposed to the pheromones (dissolved in hexane) (without eggs: pheromone; with eggs: pheromone + eggs). Means + SE of water contents and hydrogen peroxide concentrations are given (n = 5 for water content untreated; n = 8 for all other treatments). All data were evaluated by ANOVA and, for the hydrogen peroxide concentrations, by multiple pairwise t tests and a Benjamini−Hochberg P value correction (different lowercase letters in bars indicate significant differences at P < 0.01) (compare SI Appendix, Table S2). (C) Chemical structure of D. pini sex pheromone components.