Effects of ratio and amount of the two sex-pheromonal components of the diamondback moth on male behavioral response

The responsiveness of male diamondback moth to its sex pheromone was examined in the laboratory. The responses were observed in a flask after chemicals adsorbed on a piece of filter paper were provided. Male response showed a peak at a dose of 1×10-3 μg on the filter paper with 1 : 1 mixture of (Z)-11-hexadecenyl acetate and (Z)-11-hexadecenal. Response decreased when the chemicals were increased to more than 1×10-3 μg and finally was completely inhibited by 1μg of chemicals; the optimum concentration inducing male sexual behavior was determined. Optimum ratio of the mixture ranged from 8 : 2 to 5 : 5 (acetate : aldehyde) when the amount was fixed at 1×10-3 μg and no sharp perk was observed.