When plants are exposed to ozone they exhibit changes in both primary and secondary metabolism,
which may affect their interactions with herbivorous insects. Here we investigated the performance and
preferences of the specialist herbivore Pieris brassicae on the wild plant Brassica nigra under elevated
ozone conditions. The direct and indirect effects of ozone on the plant-herbivore system were studied. In
both cases ozone exposure had a negative effect on P. brassicae development. However, in dual-choice
tests larvae preferentially consumed plant material previously fumigated with the highest concentration
tested, showing a lack of correlation between larval preference and performance on ozone exposed
plants. Metabolomic analysis of leaf material subjected to combinations of ozone and herbivore-feeding,
and focussing on known defence metabolites, indicated that P. brassicae behaviour and performance
were associated with ozone-induced alterations to