Studies on Oriental Fruit Moth (Lepidopterai Tortricidae) Pheromone Micro capsales Using Various Tree Fruit Species, Cultivars, and Application Methods

摘要

The number of microcapsules containing pheromone of the oriental fruit moth, Grapholita molesta (Busck), was determined on leaves from apple, Asian and European pear, peach, sweet and tart cherry, and plum trees. In addition, we compared the number ofmicroeapsules on apple and peach leaves using a laboratory leaf dip application and a field airblast sprayer application. Finally, we compared the number of microcapsules on two apple and peach cultivars after airblast sprayer applications of microencapsulated pheromone. The bottom surface of'Gala' apple leaves had microcapsule density of 0.47, the highest among the different tree fruits. The bottoms of 'Shinko1 Asian pear had the lowest microcapsule density of 0.09 followed by the tops of 'Bluebell' plum and 'Columbia' sweet cherry leaves both with density of 0.10. The greater than 3-fold difference between the fruit leaves with the highest and lowest numbers of microcapsules may indicate the need for rate specific recommendations on different species of fruit trees. The number of microeapsules on apple and peach leaves treated with laboratory leaf dips was 8- to 60-fold greater than the number of microcapsules on field-treated leaves. Although laboratory treatments eliminated other potentially confounding field variables, they did not accurately represent microcapsule numbers on leaves treated with an airblast sprayer. There were significant differences in micro-capsule abundance on 'Delicious' and 'Gala' apple leaves and 'Encore' and 'Red Haven'peach leaves. Trichome abundance and cuticle structure may be responsible for the differences in the number of microcapsules on various tree fruit species and cultivars.