Figure 4.

Herbivory on leaves of control plants, plants treated with JA, and artificially damaged plants 6 weeks after the beginning of treatment (mean + SD). The percentage of leaf area consumed by chewing herbivores was measured on the youngest six leaves (number 1 representing the youngest leaf) of 15 plants per treatment. Treatments were conducted every 4 days by puncturing leaves (Holes) 100 times with a needle (diameter 1 mm; punctures spread regularly over the entire leaf surface) and spraying 2.5 ml of an aqueous 1-mM solution of JA on the JA leaves. Control plants remained untreated during the entire study period.