SPATIAL DISCRIMINATION BETWEEN SOURCES OF PHEROMONE AND AN INHIBITOR BY THE LIGHT-BROWN APPLE MOTH EPIPHYAS-POSTVITTANA (WALKER) (LEPIDOPTERA, TORTRICIDAE)

Inhibition of the behavioral responses of male Epiphyas postvittana mo ths by the Z isomer of the major component of the sex pheromone, E11-1 4:OAc, was studied in a wind tunnel. Inhibition was detectable at a Z isomer concentration of 10% that of the major component and was greate st when it was added to the same source as the pheromone. Inhibition d eclined rapidly as the inhibitor was moved across-wind away from the p heromone source but was largely maintained when the sources were separ ated upwind or downwind. The results showed that the insects possess a high degree of temporal resolution for odor plumes of different compo sition.