Apple, Chemical Control of Codling Moth, 1985

Abstract

Abstract Several insecticides were evaluated for their ability to provide seasonal control of the codling moth. This test was conducted in a 7-year-old apple orchard with under-tree irrigation. The experimental design was a randomized complete block with 4 single-tree replicates per treatment. All materials were applied in a dilute spray to the point of drip (approximately 400 gal per acre) with a handgun sprayer operating at 400-500 psi. Two applications were made against first generation. The first was timed to coincide with predicted 3% egg hatch or 250 degree days following first moth detected in a pheromone trap. The first cover was applied on 23 May. The second cover was applied 21 days following the first on 13 Jun. One application was made against second generation and timed at 1450 degree days after first moth on 23 Jul. This timing coincided with a predicted 28% hatch of second generation eggs. All fruit on each tree were examined after first generation. The number of shallow (stings) and deep entries were recorded. Following second generation, fruit were removed from each tree and counted. Injured fruit were collected, returned to the laboratory for examination to determine the number of shallow and deep entries. Live larvae found within fruit were saved and head capsules measured to determine instar. Codling moth adult activity was monitored using pheromone traps. Traps were examined weekly and the number of moths recorded. Pheromones were changed every 4 wk, and trap bottoms were changed after an accumulation of 30 moths. Mites were sampled from mid-Jun through mid-Sep. Twelve or 13 leaves were collected from each tree (total 50 leaves per treatment) and returned to the laboratory. Leaves were processed through a mite brushing machine and mites were counted under a dissecting microscope. Mite densities are presented as mean mites per leaf for the growing season.