Chemical control programs for Drosophila suzukii that comply with international limitations on pesticide residues for exported sweet cherries

Abstract

The recent introduction of Drosophila suzukii (Matsumura) into regions of the western United States that produce cherries, Prunus avium (L.), has resulted in the need for insecticide-based management programs close to harvest. These treatments have become problematic because of inconsistencies among export markets regarding maximum residue limits (MRLs) that are allowed for different insecticides on imported fruit. As a result, fruit that was treated and harvested in a safe manner according to the U.S. label issued by the Environmental Protection Agency may or may not qualify for export to countries that have MRLs that are lower than those of the United States, or where MRLs have not yet been established. This project addresses this issue by measuring the degradation curves of six insecticides when applied at 7 or 21 d before the initiation of harvest. Based on the results of these tests, we propose a selection of insecticides that can be used for spotted wing drosophila control, with the number of applications and sequence of insecticides used dependent on pest pressure and the number of days required between application and harvest. Three insecticides with favorable characteristics include lambda-cyhalothrin, spinosad and malathion, which allow producers to incorporate the principles of efficacy, fruit susceptibility, and resistance management and still allows for the export of fruit to all major export markets.