Comparing the efficacy of season-long chemically based management strategies for <i>Drosophila suzukii</i> in southeastern blueberry crops

<i>Drosophila suzukii</i>, is an invasive insect pest that has a major impact on small fruit production throughout the United States. Current management practices rely primarily on frequent applications of broad-spectrum insecticides. Therefore, it is important for growers to have specific information on the efficacy and residual activity of these insecticides. Field studies were conducted in Georgia on blueberries to evaluate insecticides in the southeastern United States, as well as the effectiveness of season-long treatment programs.  In semi-field bioassays, all treatment programs produced higher mortality than controls when collected directly after the treatment applications.  Some samples collected three or more days after the treatment applications still showed evidence of residual impacts. Treatment programs also showed reduced numbers of offspring produced after exposure to treated plant material. Within the treatment programs some chemicals were more effective than others, including the organophosphates, phosmet and malathion, and the pyrethroids, zeta-cypermethrin and fenpropathrin. This study shows that effective, season-long rotational treatment programs can be designed for growers, and specific programs can be selected based on exportation requirements, resistance management programs, and climate uncertainties.