Isomer Content and Other Factors Influencing Captures of Oriental Fruit Moth by Synthetic Pheromone Traps13

Abstract

Factors influencing captures of the male Grapholitha molesta (Busck) by traps baited with its synthetic sex pheromone, (Z)-8-dodecenyl acetate, and dodecyl alcohol (a synergist) were investigated. Of the 5 trap designs tested, the Zoecon Pherotrap 1, with both top and bottom sections, caught the most moths. Traps at, heights of 3 and 6 ft caught best; comparatively few moths were taken at 9 ft and almost none at ground level. Of 4 concentrations of a 1:10 combination of pheromone + synergist, 0.8 μl pheromone + 8 μl synergist caught the most moths; of 7 combinations of pheromone + synergist, 2 μl each of pheromone + synergist caught best. Addition of (Z)-8-dodecenyl alcohol to the pheromone + synergist mixture depressed moth captures. Response to the attractant was greatest between 8 and 9 PM, with response continuing at a lesser pace through the night. Most importantly, the addition of a small percentage of the E isomer to the pheromone resulted in enhanced attraction; thus, the mixture of synergist + pheromone containing 1.7% E isomer caught only 20 moths vs. 505 caught by a similar mixture with 6.7% of the E isomer.