Susceptibility of Aronia (Aronia melanocarpa) toDrosophila suzukii(Diptera: Drosophilidae)

Abstract

Drosophila suzukii is an invasive pest of cultivated fruit crops in Europe, Asia, and the Americas. However, more information is needed to understand the extent of D. suzukii utilization of wild fruit and specialty crops as suitable hosts, such as aronia (Aronia melanocarpa), for which risk assessment has not yet been established. Both laboratory bioassays and field monitoring were conducted to assess the susceptibly of aronia to D. suzukii. No-choice bioassays were conducted on damaged, destemmed, and undamaged aronia fruit. Field infestation was assessed using yeast-sugar traps for adults and fruit samples for larvae during the 2015 growing season at three farms in south-central Wisconsin. In bioassays, D. suzukii successfully completed its life cycle in damaged and destemmed aronia, while undamaged aronia did not support larval or adult development. Adult flies which emerged from damaged aronia took longer to develop and weighed less compared to adults emerging from raspberry. In the field, adults were abundant throughout the growing season (late June–late September) and larvae were detected in low numbers in ripe fruit samples collected from late August through late September. After harvest, fruit sampled from the processing and packing line revealed low numbers of drosophila larvae. Overall, these findings suggest that damaged or destemmed aronia is susceptible to D. suzukii infestation, while intact fruit is resistant to D. suzukii. In addition, the bioassays suggest that aronia may serve as a suboptimal host compared to raspberry. These findings suggest the importance of preventing fruit damage before harvest and add to a growing understanding of how wild and specialty crops, such as aronia, may affect population dynamics of this invasive fly.