The role of herbivore-induced plant volatiles (HIPVs) as indirect plant defense mechanism in a diverse plant and herbivore species; a review

Abstract

When plants are attacked by herbivores, they release plant volatiles called herbivore-induced plant volatiles (HIPVs) tothe environment to communicate with higher trophic levels. HIPVs play different ecological roles such as plant-plantinteraction, plant-herbivore interaction, tritrophic interaction and other related interactions. Attractiveness of HIPVs tonatural enemies in a tritrophic interaction varies depending on species diversity. Under natural and multiple croppingsystems, tritrophic interaction is expected to be more complex than single tritrophic interaction with one species pertrophic level. In complex tritrophic interaction, diversity of different trophic levels affects attractiveness of HIPVs tonatural enemies. From plant diversity point of view, HIPVs mixture emanating from herbivore-damaged multiple plantspecies are reported to affect behavioral responses and foraging behavior of natural enemies under laboratory and fieldconditions. Similarly, from herbivore diversity point of view, in nature, plants are commonly attacked by more than oneherbivore species. Constituents of HIPVs vary between plants infested by multiple and single herbivore species and thisaffects the behavioral responses and foraging behavior of natural enemies. This paper reviews recent findings on the roleof HIPVs as indirect plant defense in systems with simple tritrophic interaction, and in diverse plants species and diverseherbivore species.