Oviposition of spotted wing drosophila (Drosophila suzukii) in damaged and undamaged fruit

Spotted wing drosophila, Drosophila suzukii (Matsumura), has become a major agricultural pest across the United States. Unlike native Drosophila spp., D. suzukii females have a serrated ovipositor, allowing them to lay eggs in ripe or ripening soft-skinned fruits. Once eggs are laid in the fruit and hatch, maggots cause rapid deterioration of the fruit, which is a major concern for fresh-market fruit. Additionally, high reproductive rates and short generation times can result in exponential population growth rates.  Research has been conducted for some fruits such as raspberries, strawberries and blackberries, however, there are many fruits where little or no data exists regarding susceptibility to D. suzukii ovipositioning. Therefore, our research objectives were to determine if D. suzukii can oviposit in intact grapes, blueberries, raspberries, and tomatoes and to determine if previous injury to these fruits, such as physiological splitting, make the fruit more susceptible.  Our trials show that D. suzukii can oviposit in intact raspberries, blueberries and table grapes and thus, these fruits are potential hosts for D. suzukii.  However, D. suzukii was not able to oviposit in intact cherry tomatoes and wine grapes.  Despite these results with intact fruit, when the fruit had been previously damaged, raspberries, blueberries, table and wine grapes, and cherry tomatoes were all susceptible to D. suzukii ovipositioning and led to production of adult D. suzukii. These results provide an increased awareness of host susceptibility and the role that previous damage, such as physiological splitting, may play in determining the risk of D. suzukii infestation.