Challenges of climate change and air pollution for volatile-mediated plant–parasitoid signalling

Herbivore-induced plant volatiles (HIPVs) are reliable cues that parasitoids can use to locate host patches. Interactions mediated by plant volatile organic compounds (VOCs) are vulnerable to disturbance by predicted climate change and air pollution scenarios. Abiotic stress–induced VOCs may act as false signals to parasitoids. Air pollutants can disrupt signalling by degrading HIPVs at different rates and preventing the perception of olfactory signals by reducing the sensitivity of olfactory receptors or by occluding insect sensillae. As essential components of biological control programmes, efforts should be made to assess how different parasitoid species respond and adapt to HIPVs in predicted scenarios. Since providing parasitoid food sources is a promising practice for boosting biological control, parasitoid–flower interactions deserve attention. [Display omitted] •We review the impact of climate change and air pollution on tritrophic signalling.•Plant volatiles induced by abiotic stress can act as false signals to parasitoids.•Air pollutants degrade/transform olfactory cues and disrupt signalling.•Air pollution can prevent the perception of signals and affect recall and learning.