Integration of pheromonal signals and kairomonal cues in host‐finding by the parasitoid Chouioia cunea

BACKGROUND: Infochemicals mediating intraspecific (pheromones) and interspecific (kairomones) interactions play critical roles in parasitoid host location. Yet how they interact to guide foraging behavior remains poorly understood. This study investigated chemical communication between the parasitoid wasp, Chouioia cunea and its host, the fall webworm, Hyphantria cunea, with a focus on the integration of conspecific signals and host-derived cues. RESULTS: Volatile collection and gas chromatography-mass spectrometry (GC-MS) analyses identified 14 and five compounds from wasps and parasitized host pupae, respectively. Chouioia cunea females showed significant attraction to odors from both conspecific females and parasitized host pupae in behavioral assays conducted with a Y-tube olfactometer. Further, wasps showed electroantennographic responses to 18 of the 19 identified compounds, as well as attraction to their synthetic blend. However, female wasps showed strong oviposition preference for unparasitized over parasitized pupae. CONCLUSION: These results demonstrate that C. cunea integrates conspecific pheromones and host-derived kairomones to guide host location, but uses additional cues for oviposition, to avoid superparasitism. These findings provide new insight into parasitoid chemical ecology and serve as a basis for developing improved attractants for biological control.