Microencapsulatedcis- andtrans-11-tetradecenyl acetates (89:11) were sprayed onto apple trees at ca. 22 g/ha. This formulation disrupted (75–99%) the attraction of maleArgyrotaenia velutinana(Walker) to monitoring traps baited withcis- andtrans-11- tetradecenyl acetates (92:8) and dodecyl acetate, the natural pheromone blend of this species. Males held in smail cages and exposed to this formulation mated as frequently as a control group, indicating that the males' mating initiative was not suppressed.