Ecological Dynamics of Volatile Organic Compound-Mediated Interactions in With Parasitoids and Herbivores.

In the evolutionary arms race between plants and herbivores, sophisticated mechanisms of indirect plant defense play a pivotal role. This study investigated the role of volatile organic compounds (VOCs) in attracting the parasitoid spp. to , while also providing insights into the interactions among , the herbivore , and spp. in a tritrophic context. This study utilized field surveys, olfactometer experiments, and Gas Chromatography-Mass Spectrometry (GC-MS) analysis to investigate the role of VOCs. Field surveys showed a 54.6% egg parasitism rate, with quadrats containing and larvae attracting more spp. than those with the plant alone. In olfactometer bioassays, spp. preferred leaves damaged by a pattern wheel simulating herbivore damage, with 46.8% choosing these leaves over undamaged controls. Leaves treated with larval saliva were similarly attractive, drawing in 48.7% of spp.; however, the difference in attraction between saliva-treated and untreated leaves was not statistically significant, suggesting saliva may not be central to spp. attraction. GC-MS analysis identified VOCs in damaged leaves, including hexyl acetate, cyclohexene, δ-cadinene, α-pinene, and β-caryophyllene, while saliva-treated leaves showed minimal amounts of exo-isocitral and β-pinene. Despite complex responses, our analysis suggests these saliva-induced compounds do not significantly boost spp. attraction. This finding implies that while the VOC response to damage and saliva application is multifaceted, serving multiple defensive functions, the amount of these saliva-induced compounds may be insufficient to substantially influence the behavior of spp. toward damaged leaves. Our results emphasize the role of VOCs in 's indirect defense mechanisms and contribute to understanding the ecological dynamics within plant-parasitoid-herbivore interactions. Moreover, our findings suggest new avenues for exploring the ecological and evolutionary roles of chemical signals, highlighting the complex interactions facilitated by these cues in plant defenses.