TRITROPHIC INTERACTIONS: THE INTERCONNECTEDNESS OF LIFE, THE DELICATE BALANCE AND THE VIBRANT SYNERGY THAT SUSTAINS THE AGRICULTURAL ECOSYSTEM

Abstract

The natural defence of the plants may act directly or indirectly against pests. The direct defence by the plants is by affecting the preference of host plant or survival and reproductive success which is mediated by mechanical protection or by secondary metabolites. The indirect defence against insects is induced by the release of blends or combinations of volatiles that may attract natural enemies. Plants emit volatile and non-volatile compounds to defend themselves from herbivore attack. The volatiles released by the plants play a vital role as signals in tritrophic interactions. The three trophic levels involved are plants (1st trophic level), herbivores (2nd trophic level) and the natural enemies that include predators and parasitoids (3rd trophic level). The importance of third trophic level i.e., natural enemies was initially emphasized by Price et al. (1980). The third trophic level is considered as part of a plant's battery of defences against herbivores.  Multiple factors, including plant species, genotype, age, herbivore species, the severity of the attack, abiotic conditions, or any combination of these, may affect the release of HIPVs at the plant level. Initial observations of plant-to-plant communication were met with doubt, but it is now generally accepted that plants react to the stress signals of their neighbours. At the plant level, tritrophic interactions are shaped by the interplay between biotic and abiotic stressors. Ecosystem services rely on interactions among organisms, particularly in tritrophic interactions involving plants, herbivorous pests, and their natural enemies. These interactions are vital for sustainable agriculture and biocontrol services. Trophic cascades, which affect food webs by causing changes that impact multiple levels, can influence biological control in either positive or negative ways.