Volatile emission by S. wertheimae galls and P. atlantica leaves and infructescences . (a) Emission of total volatiles (ANOVA followed by LSD: F = 4.139, n = 6, P = 0.046). Different letters indicate significant differences (b) Comparison of single and total volatile emission in intact and mechanically wounded S. wertheimae galls. (single volatiles: Wilcoxon Matched Pairs Tests, P < 0.05; total emission: Wilcoxon Matched Pairs test, Z = −2.023, n = 6, P = 0.043). Bars show means ± standard errors.