Secondary metabolite concentrations in galls of S. wertheimae and leaves and fruits of P. atlantica. (a) Total tannins (Kruskal-Wallis ANOVA, Chi = 12.000, n = 6, P = 0.002). (b) Total terpenes (Kruskal-Wallis ANOVA, Chi = 14.216, n = 6–8, P = 0.001). Bars show means ± standard errors. Different letters above bars indicate significant differences.