Understanding Spotted Wing Drosophila (Drosophila suzukii) Oviposition Preferences and Host Suitability of soft-skinned fruits

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 which allows them to lay eggs in ripe or ripening soft-skinned fruits. Once eggs have been laid in the fruit and have hatched, maggots cause rapid deterioration of the fruit which is a major concern for fruit being sold as fresh-market. Additionally high reproductive rates and short generation times result in exponential population growth rates.  Research has been conducted for soft-skinned fruits such as raspberries, strawberries and blackberries, however, there are many soft-skinned fruits where there is little or no data regarding their susceptibility to D. suzukii. Therefore, our research objectives were: 1) to determine if D. suzukii can oviposit in intact grapes, blueberries, and tomatoes and 2) to determine if previous injury to these fruits, such as splitting, make the fruit more susceptible to oviposition.  Our trials show that intact blueberries and table grapes are susceptible to ovipositioning and are potential hosts for D. suzukii.  However, intact cherry tomatoes and wine grapes were not susceptible to ovipositioning.  Despite the results from intact fruit, when the fruit was previously damaged, blueberries, table and wine grapes, and cherry tomatoes all were susceptible to ovipositioning and led to the eventual 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.