Role of Plant Volatiles, Pest-Resistant Varieties and Transgenics in Tri-trophic Interactions

Abstract

The interaction between plants, parasites and parasitoids (tri-trophic interaction) is of great significance in developing newer pest-resistant crop varieties. One of the important defence mechanisms of a plant infested by an insect pest is to release volatiles that can attract parasitoids. These volatiles are broadly classified as herbivore-induced plant volatiles (HIPVs). HIPVs are also involved in communication between neighbouring plants and different parts of the same plant. The volatiles send clues to the other community members at different trophic levels that influence their interactions. Many parasitoids rely on these volatiles to detect the presence of their hosts. When pests attack plants, plants try to attract predators and parasitoids of the attacking herbivores with the help of the volatile chemicals that can provide various information like location, activity and developmental stage of the attacking herbivore. The release of pest-resistant varieties of various crops also influences the tri-trophic interactions which may result in changing the behaviour of pests/predators/parasitoids. This chapter elaborates the various plant volatiles and their role in the tri-trophic interaction. The introduction of various pest-resistant (transgenic) varieties and how they influence these tri-trophic interactions is also discussed.