Influence of mating on responses of Helicoverpa armigera moths to synthetic plant volatiles

Responses of mated and unmated Helicoverpa armigera female moths to various synthetic plant volatile compounds were studied using a two-choice olfactometer. Results suggest that mated moths are both more active in the olfactometer and more responsive to most compounds than unmated ones. Even in a blank olfactometer (ie, no volatile) or where only the carrier canola oil was present, there was a trend for more mated than unmated moths in the test chamber, although the differences were not statistically significant. There was also a trend for the difference between mated and unmated moths to be greater with more attractive compounds. We also compared mated females with females which had been confined with another female for an equivalent period to that which the mated females spent with males, to determine whether it was mating per se that influenced responsiveness in the olfactometer, or just confinement with another moth. There was no difference between these two groups of females, suggesting it is mating which is the crucial factor.