Selective actions of plant-based biorational insecticides: Molecular mechanisms and reduced risks to non-target organisms

Plant-based biorational insecticides such as essential oils and extracts are complex mixtures of molecules that exhibit selective toxicity toward insect pests while minimizing harm to nontarget organisms (NTOs) such as pollinators, parasitoids, and predators. Recent investigations using clove (Syzygium aromaticum), Negramina (Siparuna guianensis), and common fig (Ficus carica) indicate that their essential oils and extracts generally exhibit lower toxicity to beneficial organisms than to target pests, potentially due to ecological factors like application timing. This review focuses on physiological selectivity, which involves preferential interactions between plant compounds and targets in pests versus NTOs. Advances in computational methods and genetic engineering enable the prediction of these interactions, revealing that plant compounds (e.g. β-caryophyllene, psoralen, sesquirosefuran, and eugenol) bind more effectively to specific enzymes and receptors in pest insects. By exploring these mechanisms, we highlight the potential of plant-based insecticides to reduce risks to NTOs and their role in sustainable pest management programs.