Broad-spectrum insecticides are the standard control method used in tree fruit orchards to control periodical cicadas (Magicicada spp.) and to reduce associated oviposition injury to woody host plant tissue. The purpose of this study was to evaluate the effectiveness of two organically approved methods; foliar applications of Organic Materials Review Institute (OMRI)-registered insecticides; and physical exclusion to manage periodical cicada oviposition injury in a commercial apple orchard. Insecticides evaluated included kaolin clay and neem + karanja oil (mixed in a 1:1 ratio). The physical exclusion method involved covering trees with polypropylene fabric. Oviposition injury assessed during the study included the number of periodical cicada eggnests, eggnests per scar, and flagged branches. Neither kaolin clay nor neem + karanja oil significantly reduced periodical cicada oviposition injury compared with the untreated control. Trees covered with exclusion fabric sustained no injury from periodical cicadas. Despite the injury sustained by insecticide-treated and control trees, the extent of periodical cicada oviposition with several tree growth characteristics (tree height, tree canopy width, and trunk circumference) was not significantly correlated.

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