Chemical Signaling and Integrated Strategies for Biological Control in Crop Agroecosystems

Abstract

Simple Summary Insect pests cause serious losses in many crops, and their control often depends heavily on chemical pesticides. Although pesticides can be effective, their repeated use may create environmental risks and can also affect beneficial insects that naturally help control pests. Plants, however, have their own ways of defending themselves. When attacked by herbivorous insects, many plants release specific odors that can be detected by predators and parasitoids. These beneficial insects use herbivore-induced plant volatiles, including terpenoids, green leaf volatiles, and compounds such as methyl salicylate, to locate pest-infested plants and reduce pest populations. This review explains how plant odors, insect pheromones, and other chemical cues can be used to improve biological control in agriculture. It also discusses how these signals can be combined with habitat management, flowering plants, push–pull systems, attract-and-reward strategies, plant breeding, and genetically engineered crops. Together, these approaches may support natural enemy conservation, although their effects on pest suppression, crop yield, and pesticide use must be confirmed under field conditions.