Aphid and episodic O 3 injury in arugula plants ( Eruca sativa Mill) grown in open-top field chambers

Abstract

Aphid attacks and tropospheric ozone (O 3) cause stress and considerable damage in both wild and cultivated plants. Induced defense responses to aphid attacks and O 3 exposure share signaling pathways with common points. We investigated the plant–aphid interaction under O 3 exposure using open-top O 3 chambers. Ozone leaf injury was lower in aphid-infested plants than in aphid-free plants, although herbivore damage was not evident. Aphid population growth was strongly affected by previous exposure to O 3 but no direct effect of O 3 was observed. The possibility that during O 3 episodes, herbivores may reduce O 3 damage on host plants and that the offspring of the exposed aphids have lower population growth rates opens new and intriguing questions about potential effects of future increased tropospheric O 3 levels on plant–insect interactions.