Trace amount of minor pheromone components play a vital role in sexual communication of moth species.Helicoverpa armigera use (Z)-11-hexadecenal (Z11-16:A1d) and (Z)-9-hexadecenal (Z9-16:A1d) as the principal sex pheromone components, and (Z)-9-tetradecenal (Z9-14:Ald) as the trace component.In this study, we first used wind tunnel to prove Z9-14:A1d plays dual roles in pheromone communication of H.armigera, then used single sensillum recording to characterize olfactory sensilla responding to the three chemicals, and finally used in vivo calcium imaging to study projection of their related olfactory sensory neurons (OSNs) in the antennal lobe (AL).