Harnessing semiochemicals for parasitoid-based biological control: from laboratory identification to field applications

Parasitoids are vital biological control agents in agricultural pest management, with mating and parasitism as their core behaviors essential for reproduction and survival. In recent decades, advanced analytical techniques, such as gas chromatography-electroantennographic detection (GC-EAD), have enabled the identification of key semiochemicals that regulate parasitoid behavior. Notably, studies on Campoletis chlorideae (Hymenoptera: Ichneumonidae) have elucidated the mechanisms of sex pheromone communication, advancing our understanding of pheromonal signaling in parasitoids. Moreover, plant-derived synomones and host-derived kairomones serve as pivotal chemical cues for host location, underpinning tritrophic (plant-pest-parasitoid) interactions. The functional characterization of olfactory receptors tuned to herbivore-induced plant volatiles and kairomones, achieved through ectopic expression systems, has further clarified the molecular mechanism underlying semiochemical-mediated behaviors. Synthetic biology offers promising avenues for manipulating parasitoid behavior by leveraging genetic and metabolic engineering of plants and yeast to release critical synomones and kairomones, thereby improving parasitoid recruitment. This review synthesizes the role of semiochemicals in mediating parasitoid behaviors, evaluates methodologies for behavioral manipulation, and explores the potential and limitations of integrating synthetic biology with semiochemicals to advance sustainable pest management.