Behavioral observations of codling moth, Cydia pomonella, in orchards permeated with synthetic pheromone

Mating disruption of codling moth, Cydia pomonella, was studied in apple or chards treated with the main pheromone compound codlemone, (E,E)-8,10-dodec adienol, and a blend of codlemone and codlemone acetate, (E,E)-8,10-dodecad ienyl acetate, a strong pheromone antagonist. Codlemone alone and the phero mone/antagonist-blend had a similar effect on the behavior of males emergin g into air-permeated orchards. Male flights within tree canopy and upwind o rientation along tree rows were strongly enhanced by both formulations, com pared to untreated plots. However, the codlemone/codlemone acetate-blend in creased the rate of cross-wind and downwind flights within the orchard, com pared to codlemone alone. The major difference between these two formulatio ns was that males from nearby, untreated orchards were attracted towards or chards treated with codlemone, but not towards treatments with codlemone/co dlemone acetate. Additional tests were done with an equilibrium blend of co dlemone and its geometric isomers. Aerial pheromone concentrations in the o rchards were recorded by the field electroantennogram technique. Decreasing pheromone concentrations towards the upper part of the tree canopy, togeth er with the stimulation of male flight activity by synthetic pheromone expl ains failures to control codling moth at high population densities with cur rent dispenser formulations.