Integrating airborne chemical ecology with informed intercropping for sustainable crop protection

The role of volatile organic compounds (VOCs) in plant-insect interactions has been studied in detail in recent decades, especially in the context of environment-friendly integrated pest management (IPM) in agroecosystems. Field-based study and behavioural investigations have shown that specific VOCs (or combinations of VOCs) of companion crops are crucial in diverting phytophagous insects from main food or cash crops, along with attracting beneficial insects which decimate pest species. The functional mechanisms of these olfactory cues, however, are not always clear and distinctive, especially since these ecological interactions are highly variable. The complex 'odourscapes' occurring in mixed cropping systems are determined by species-specific interactions, local climate, prevalent agricultural/landscaping practices, and other environmental factors which need to be examined in localized contexts. This review aims to cover the dynamics and mechanisms of VOCs mediating plant-insect interactions in mixed crop settings, the variables and technical constraints to be considered for implementing these interactions for cost-effective IPM, and potential challenges presented by ecological fine-tuning of such interactions.