Herbivore-Induced Plant Volatiles: A Key Mechanism in Tritrophic Interactions

What Are Herbivore-Induced Plant Volatiles (HIPVs)?

Herbivore-induced plant volatiles are chemical signals released by plants in response to herbivore attack. These compounds serve as a form of defense, attracting natural enemies of the herbivores such as predators and parasitoids.

The release of HIPVs is a sophisticated adaptive strategy that helps plants mitigate damage from herbivores and maintain their fitness.

How Do Plants Produce HIPVs?

Plants produce HIPVs through the biosynthesis of volatile organic compounds (VOCs) in response to mechanical damage or chemical cues from herbivore saliva. This process is regulated by complex signaling pathways involving hormones like jasmonic acid and ethylene.

The production and release of HIPVs can be rapid, often occurring within minutes after a herbivore attack.

Role of Wind in HIPV Dispersal

Wind plays a critical role in the dispersion of HIPVs. Volatiles are released into the air and can be carried by wind currents, increasing their range and effectiveness as signals.

The advection of volatiles by wind creates concentration gradients that guide natural enemies to locate their prey or host plants.

Mechanisms of Parasitoid Wasp Navigation

Parasitoid wasps use olfactory cues from HIPVs to navigate and locate their hosts. They employ a sophisticated cast-and-surge strategy, zig-zagging crosswind to detect increasing concentrations of volatiles, followed by straight upwind surges towards the source.

This navigation technique is highly efficient and allows for precise localization of host plants or herbivores.

Frequently asked questions

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Everything above runs in your browser — open Herbivore-Induced Plant Volatiles Simulator (2D) and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.