Bagging Apple Fruit for Codling Moth Control in Western Montana

Codling moth ( Cydia pomonella ) is a major insect pest of apple Malus domestica ). If unmanaged, then codling can infest nearly all apples in an orchard, where the flesh-tunneling larva leave frass-laden tracks fruit. Insecticide-based management requires accurate application timing (typically based on adult and/or degree-day monitoring) and multiple spray applications. Both season-long commitment to monitoring limited familiarity with insecticides, tools, proper procedures prevent small-scale or backyard grower from effectively limiting fruit damage. In addition, increasing segment growers interested nonchemical alternatives. Bagging fruitlets early season could be simple effective method for this subset growers. At our research orchard Corvallis, MT, we tested combining thinning bagging using plastic bags first nylon second season. Plastic reduced incidence damage 34% 10%, but european earwig Forficula auricularia frass, which was found more than 50% plastic-bagged apples, made harvesting unappealing. We during year study. These did not significantly reduce moth. soluble solids content titratable acidity were higher unbagged study, whereas color measurements indicated bagged greener shaded side Failure may have been attributable eggs laid before bagging, burrowing through improper bag methods. Further assess whole-tree bags, addition rubber bands twist ties when applying pretreatment horticulture oil, dipping kaolin clay application; however, these steps add time increase costs, discourage grower. Overall, results indicate that holds promise management; further work needed optimize methodology.