Abstract
Plants release volatiles induced by herbivore feeding that may affect the diversity and composition of plant-associated arthropod communities. However, the specificity and role of plant volatiles induced during the early phase of attack, i.e. egg deposition by herbivorous insects, and their consequences on insects of different trophic levels remain poorly explored. In olfactometer and wind tunnel set-ups, we investigated behavioural responses of a specialist cabbage butterfly (Pieris brassicae) and two of its parasitic wasps (Trichogramma brassicae and Cotesia glomerata) to volatiles of a wild crucifer (Brassica nigra) induced by oviposition of the specialist butterfly and an additional generalist moth (Mamestra brassicae). Gravid butterflies were repelled by volatiles from plants induced by cabbage white butterfly eggs, probably as a means of avoiding competition, whereas both parasitic wasp species were attracted. In contrast, volatiles from plants induced by eggs of the generalist moth did neither repel nor attract any of the tested community members. Analysis of the plant’s volatile metabolomic profile by gas chromatography-mass spectrometry and the structure of the plant-egg interface by scanning electron microscopy confirmed that the plant responds differently to egg deposition by the two lepidopteran species. Our findings imply that prior to actual feeding damage, egg deposition can induce specific plant responses that significantly influence various members of higher trophic levels.
Highlights
A major challenge in ecology is to understand how phenotypic plasticity of plant traits affects the complexity and dynamics of plant-associated communities
Egg Parasitoid At 24 hours after oviposition by P. brassicae, plants start to express a necrotic zone below the egg clutches that sometimes led to egg desiccation or egg dropoff at 72 hao (Figure 1B)
There was no effect of plant phenotype on the number of wasp offspring that emerged from parasitized host eggs (GLM; x21 = 0.01, P = 0.91), but there was an effect of egg age (GLM; x21 = 6.70, P = 0.01)
Summary
A major challenge in ecology is to understand how phenotypic plasticity of plant traits affects the complexity and dynamics of plant-associated communities. Plants emit a blend of volatile organic compounds that affect interactions with organisms belonging to the arthropod community of the plant [4,5,6,7,8]. These herbivoreinduced plant volatiles (HIPVs) can consist of hundreds of compounds, such as terpenoids, green leaf volatiles and benzenoids and have been shown to act as repellents and/or attractants for herbivores and their natural enemies [4,5,8]. HIPV-mediated effects on different trophic levels imply an extensive effect of plants in structuring associated communities [4,10,13]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
