Susceptibility of Aronia (Aronia melanocarpa) to Drosophila suzukii (Diptera: Drosophilidae)
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.
The presentations and recordings are now available to all members that attended the 2017 MAA Annual Conference.
The USDA-ARS North Central Regional Plant Introduction Station (NCRPIS) in Ames, Iowa hosted a group of Aronia growers on September 6, 2016 led by Horticulturist, Jeff Carstens. Forty lines of native, North American species of Aronia berries are on display, including Aronia melanocarpa, Aronia x prunifolia, and Aronia arbutifolia. The majority of these collections were collected and donated by Dr. Mark Brand (University of Connecticut) from native populations throughout the eastern United States.
Agronomic variation was evident throughout the field plots including vigor, growth habit, yield, berry size, maturity date, plant height, and plant density. For most consumers, Aronia berries tend to be quite astringent and thus are commonly incorporated or processed into finished products such as jams, salsa, wine, juice, powders, etc. As with any comprehensive collection of genetically diverse germplasm collected across a species’ native range, variation for agronomic traits exists, and variation for taste can easily be noted. In addition to the field plot tour, visitors were provided with cups of fruit representing 13 different A. melanocarpa lines and a commercial standard, A. mitschurinnii ‘Viking’. Each person was asked to execute a taste test of the 14 samples harvested that morning using a 1-9 scale, with 1 = poor tasting, 5 = acceptable, and 9 = exceptional tasting.
Of the 14 samples provided for tasting, the commercial standard ‘Viking’ ranked 10th with a taste rating average of 5.3. The top two Aronia lines with highest average taste ratings were Ames 30007 and PI 662003, with ratings of 7.7 and 7.4, respectively. BRIX readings for Ames 30007 and PI 662003 were taken shortly before the tour at 18.3 and 20.5, respectively. BRIX readings for ‘Viking’ averaged 14.6. One of the participants pointed out that PI 662003 has the potential to be mechanically harvested. Both Ames 30007 and PI 662003 are adapted lines for the Midwest exhibiting dense growth and average vigor and are currently available for distribution via the NCRPIS. At NCRPIS, PI 662003 has tested one of the highest BRIX readings (26.8 approximately 14 days post peak maturity) out of all Aronia accessions tested to date. Peak fruiting for PI 662003 typically occurs the first week in September. Images of Aronia accessions and associated data can be found online. Additional information and germplasm requests may be provided upon request by contacting Jeff Carstens at firstname.lastname@example.org.