Attraction Behavior and Functional Response of Orius insidiosus to Semiochemicals Mediating Rose–Western Flower Thrips Interactions

The Western Flower Thrips ( Frankliniella occidentalis ) constitutes a significant threat to rose greenhouses in Colombia. An eco-friendly approach to managing this pest involves using the predatory bug Orius insidiosus . The pest and its predator’s food search and selection mechanisms are influenced by ecological interactions mediated by volatile organic compounds (VOCs) emitted during plant–pest interactions. To investigate the role of VOCs in the foraging and host-selection behaviors of O. insidiosus , we conducted functional response assays in greenhouses and olfactometry experiments in laboratory settings. These experiments used flowers from two rose cultivars, with and without female adult thrips, over 24, 48, and 72 h. Functional response analysis revealed a shift in O. insidiosus foraging behavior based on the duration of thrips interaction with rose flowers, transitioning from a Type II to a Type III functional response between 24 and 48 h in the ‘Freedom’ cultivar. The maximum consumption rates increased significantly, from 7.98 individuals at 24 h to 16.18 individuals at 48 h, before slightly decreasing to 14.37 individuals at 72 h. This shift coincided with an increase in O. insidiosus preference for thrips-infested ‘Freedom’ flowers over time, with selection proportions rising from 0.37 at 24 h to 0.46 at 72 h, suggesting a learning effect on prey-searching behavior mediated by VOCs. Olfactometry analyses revealed that O. insidiosus did not respond to the same VOCs that attracted F. occidentalis during flower infestation. However, O. insidiosus responded to certain VOCs likely associated with floral resources such as nectar and pollen, which also attract pollinators and zoophytophagous predators. This observation suggests a potential overlap in the chemical cues used by O. insidiosus for distinct ecological purposes. These findings highlight the complex chemical ecology underlying predator–prey interactions in agroecosystems and underscore the importance of considering VOCs in shaping the foraging behavior of natural enemies and their interactions with insect pests.