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

Factors influencing captures of the male Grapholitha molesta</it> (Busck) by traps baited with its synthetic sex pheromone, (Z</it>)-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</it>)-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</it> isomer to the pheromone resulted in enhanced attraction; thus, the mixture of synergist + pheromone containing 1.7% E</it> isomer caught only 20 moths vs. 505 caught by a similar mixture with 6.7% of the E</it> isomer.