USE OF PUFFERS FOR DISRUPTION OF SEX-PHEROMONE COMMUNICATION AMONG NAVEL ORANGEWORM MOTHS (LEPIDOPTERA, PYRALIDAE) IN ALMONDS, PISTACHIOS, AND WALNUTS

Machines for dispensing puffs of pheromone at preselected time interva ls, containing (Z,Z)-11,13-hexadecadienal, a sex pheromone component o f the female navel orangeworm, Amyelois transitella (Walker), math wer e positioned at 40-m separations around the perimeters of square 16-ha blocks of pistachios, almonds, and walnuts. With a 30-min puff night interval, which continued throughout the day and night for up to 5 d; these puffers delivered an effective release rate of 23 mg of (Z,Z)-11 ,13-hexadecadienal per ha/d within each 16-ha block. The resulting phe romone permeation of the air completely prevented males of the navel o rangeworm from locating females used as bait in traps in the centers o f the blocks that were >200 m from the closest puffer. In a smaller, s quare walnut block of 4.4 ha, with puffers located 30 m apart along th e perimeter, less-than-complete communication disruption occurred, eve n though the female-baited traps were now only approximate to 100 m fr om the closest puffer.