Fig. 3. Oviposition preference of P. brassicae under laboratory conditions for undamaged cabbages exposed under ambient ozone (A) and enriched ozone levels (B) to either
undamaged (amb-cr-VOC and ozo-cr-VOC, respectively) or herbivore-infested conspecifics (amb-ir-VOC and ozo-ir-VOC, respectively). Statistical significance of differences
between treatments were tested with paired-sample t-test (n = 25 for treatments under ambient ozone levels and n = 27 for treatments under enriched ozone levels). Bars
represent mean ( SE) percentage of eggs.