RESUMO
The composition of the sex pheromone gland of the lightbrown apple moth, Epiphyas postvittana (Walker) was re-investigated. In addition to the two previously identified compounds, (E)-11-tetradecenyl acetate (E11-14Ac) and (E,E)-9,11-tetradecadienyl acetate (E9E11-14Ac), seven additional candidate pheromone compounds were identified: (E)-11-tetradecen-1-ol (E11-14OH), tetradecyl acetate, hexadecanal, (E)-11-hexadecenyl acetate (E11-16Ac), hexadecyl acetate, octadecanal, and octadecyl acetate. Gas chromatographic-electroantennographic detection analysis showed that only four (of the nine) compounds (E11-14OH, E11-14Ac, E9E11-14Ac, and E11-16Ac) elicited electrophysiological responses. When either E11-14OH or E11-16Ac were tested at various ratios in three-component blends with both E11-14Ac and E9E11-14Ac, no increase in trap catch was observed compared to that to the previously identified binary blend. However, when these two compounds (1% E11-14OH and 0.5% E11-16Ac) were both added to E11-14Ac and E9E11-14Ac, trap catch was roughly double that to the previously identified binary blend alone. The new four-component blend should be more sensitive for detecting this economically important insect, especially in low population areas (i.e., in newly invaded habitats). In addition, this new blend may enhance pheromone control of this pest, through approaches such as mating disruption, lure and kill, and mass trapping.