Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is an invasive, polyphagous vinegar fly with high fecundity and short generation time. Drosophila suzukii, or ‘spotted-wing Drosophila’ has spread quickly across the United States and has quickly become the main pest of concern in tart cherry production. Millions of dollars are spent each year on chemical and labor costs to address this invasive pest. Current management tactics rely upon multiple applications of broad-spectrum insecticides. As populations of D. suzukii resistant to spinosyns and pyrethroids have recently been found in California, alternative management strategies are needed to reduce dependency on chemical control. Recent releases of classical biological control agents have begun across the United States, but their ultimate establishment and potential impact is yet unknown. Innovative methods of cultural and biological control could help restore integrated pest management (IPM) of D. suzukii in cropping systems. This thesis investigates cultural control and biological control methods for managing D. suzukii infestation in post-harvest fruit waste as means of reducing overall populations within an area and potentially decreasing the need for other management methods. Orchard systems often manage disposal of post-harvest crops consisting of any ripe, overripe, and decomposing fruit which may function as a reproductive source for pests. Crushing fruit or adding 15% or 25% organic poultry manure by volume were identified as effective cultural control methods of decreasing the number of D. suzukii and non-suzukii drosophila on post-harvest cherry waste. Adding Hermetia illucens (Linnaeus) (Diptera: Stratiomyidae) larvae to D. suzukii infested fruit waste was found to limit D. suzukii infestation. These cultural and biological control methods can be integrated into existing management programs to help reduce in situ populations of D. suzukii without further addition of insecticides.
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