Helicoverpa armigera (Lepidoptera: Noctuidae) is a widespread kind of pest in Iran and many countries around the world which are economically important. )Z(-11-hexadecenal has been identified as a major component of the female sex pheromone of H. armigra moths. In the present study, gas chromatography-mass spectrometry (GC–MS) was used for the identification and determination of (Z)-11-hexadecenal. (Z)-11-hexadecenal is a long-chain aliphatic aldehyde. It was also measured by bacterial bioluminescence assay based on Luciferase-FMNH2 complex, NADH, aldehyde and O2 as a sensitive and selective method. The detection limit of )Z(-11-hexadecenal was obtained 0.019 mg/L in the linear range of 0.05–4.5 mg/L by the bioluminescence assay and the GC–MS analysis amount was 1.5 mg/L with the linearity range of 5–50 mg/L. The relative standards deviation for three measurements was 1.92 and 5.7% by bioluminescence assay and GC–MS, respectively. The average amount of (Z)-11-hexadecenal in sex pheromone per moth in 2–3 days old virgin female with the bioluminescence assay and GC–MS were obtained 3.2 and 3.02 ng ml−1, respectively. Afterward, the amount of (Z(-11-hexadecenal was compared with 8–10 days old adult females by bacterial bioluminescence assay.
