Chemical Signaling and Integrated Strategies for Biological Control in Crop Agroecosystems

Food security faces significant challenges due to the growing threat of insect pests and global climate change, making it essential to adopt sustainable agricultural strategies. Plants possess intrinsic defense systems that are activated in response to herbivore attack, including the emission of specialized volatile organic compounds (VOC) known as herbivore-induced plant volatiles (HIPVs). These volatiles aid the foraging of natural enemies (predators and parasitoids), thereby contributing to biological control of pest populations. Harnessing these chemical defense mechanisms offers a promising avenue for pest management, although natural enemy attraction does not necessarily result in pest suppression or increased crop yield. This review synthesizes plant and insect-derived chemical signaling mechanisms with direct relevance to biological control in crop agroecosystems, including field crops, orchards, vegetable systems, and protected cultivation. We emphasize recent applied research while retaining selected foundational studies that established the principal concepts and mechanisms underlying chemically mediated pest management. Considering the importance of chemical signaling in sustainable agriculture, we propose four key research directions: (1) optimizing plant defense induction mechanisms; (2) integrating HIPVs with natural enemy pheromone-based attractants; (3) combining habitat management with the provision of plant-derived food resources; and (4) harnessing plant defenses through breeding and infochemical-based genetically modified crops. Additionally, we examine the potential impacts of environmental stressors on plant-herbivore chemical communication, underscoring their importance for resilient and environmentally sustainable agricultural systems.