Datensatz

Zusammenfassung

Plants that are subject to insect herbivory emit a blend of so‐called herbivore‐induced
plant volatiles (HIPVs), of which only a few serve as cues for the carnivorous enemies to
locate their host. We lack understanding which HIPVs are reliable indicators of insect
herbivory. Here, we take a modelling approach to elucidate which physicochemical
and physiological properties contribute to the information value of a HIPV. A leaflevel
HIPV synthesis and emission model is developed and parameterized to poplar.
Next, HIPV concentrations within the canopy are inferred as a function of dispersion,
transport and chemical degradation of the compounds. We show that the ability of
HIPVs to reveal herbivory varies from almost perfect to no better than chance and
interacts with canopy conditions. Model predictions matched well with leaf‐emission
measurements and field and laboratory assays. The chemical class a compound belongs
to predicted the signalling ability of a compound only to a minor extent, whereas compound
characteristics such as its reaction rate with atmospheric oxidants, biosynthesis
rate upon herbivory and volatility were much more important predictors. This study
shows the power of merging fields of plant–insect interactions and atmospheric chemistry research to increase our understanding of the ecological significance of HIPVs.