Date of Award


Degree Name

MS in Agriculture - Plant Protection Science


Horticulture and Crop Science


David Headrick


Codling moth, Cydia pomonella[Lepidoptera: Tortricidae], is a major entomological pest of apples, pears, and walnuts cross the world (Pajac et al. 2016). Female codling moths lay eggs on the apple exocarp and larvae burrow within the fruit causing economic losses to fruit growers.Organic apple orchards in San Luis Obispo, CA currently have three codling moth, Cydia pomonella,control options commercially available including granulovirus (CpVG), spinosad, and mating disruption. In field tests on apple (Malus), we compare percent fruit injury between treatments of granulovirus (2.43 oz/ha Cyd-X® organically approved, Certis USA, Columbia MD), spinosad (4.05 oz/ha Entrust® Naturalyte® organically approved WP formation, Dow AgroSciences, Indianapolis IN), and a control. We also compared mating disruption in form of codling moth Codlemone® sex pheromone (257 ties/ha (506 mg)/acre Isomate®-OFM TT organically approved Pacific Biocontrol Corporation Vancouver, WA) against a control. Delta taps and 1 mg pheromone lures were used to trap males and track the degree day (DD) model for the two orchard’s codling moth populations to determine application timing for each treatment. A preliminary DD model was used based on the University of California at Davis Agricultural Extension codling moth DD model.

During 2016 trialsno detectible control was provided by spray treatments with an average fruit injury of 26% control, 23% granulovirus, 28% spinosad. During 2016 trialsno detectible control was provided by mating disruption with an average fruit injury of 16% control and 16% pheromone. During 2017 trials there was detectible control provided by the treatments to the crop by both spray treatmentsand pheromone ties. 2017 average fruit injury for spray treatments was 51% control, 20% granulovirus, and 14% spinosad. 2017 average fruit injury for mating disruption was 29% control and 6% pheromone. Data suggest underlying relationship between location specific climate factors, cultivars, codling moth populations, and treatment efficacy.