Sustained-flight tunnel responses of male lightbrown apple moth to synthetic sex pheromone

ABSTRACT. The upwind flight response of individual male lightbrown apple moths, Epiphyas postvittana (Walker), to twenty combinations of the two pheromone components, (E)-11-tetradecenyl acetate (E11-14:OAc) and (E,E)-9,11-tetradecadienyl acetate (E,E-9,11–14:OAc), was observed in a sustained-flight tunnel. At the lowest dosage of E11-14:OAc tested (3 μg), a significantly greater percentage of males flew upwind to and landed at a source emitting 10% E1,E-9, 11–14:OAc than to all other sources. As the source dosage was increased, males showed decreased specificity of upwind flight to ratios of the two components. However, at the highest dosage of E11-14:OAc tested (300 μg), the response specificity of males shifted to blends containing lower percentages of E,E-9,11–14:OAc. The addition of tetradecyl acetate to a blend of the two components did not result in any detectable increase in male response. Analyses of the pheromone glands of individual female Iightbrown apple moths showed that females produced a range of ratios of E11-14;OAc:E,E-9,11–14:OAc from 100:2.2 to 100:11.4 with a median of approximately 100:7, reasonably paralleling the peak response of males. Pre-exposure of males to a blend of the two components, followed by exposure to E11-14:OAc alone (previously reported as a 'memory' effect) resulted in no significant response to E11-14:OAc alone.