Marquette wine grape.

2018-19 Rapid Ag: Spotted Wing Drosophila Risk and Management Solutions for the Wine Grape Industry

May 12, 2017

Principle Leader

Bill Hutchinson


Department of Entomology, MN Extension IPM Program

Funding Awarded

  • Fiscal Year 2018: $81,281
  • Fiscal Year 2019: $81,281

The Problem

Spotted Wing Drosophila (SWD) is a classic invasive pest, arriving in the U.S. without any known significant natural enemies to keep populations in check (Asplen et al.2015). With 50% of grape growers expecting to expand vineyards in the future and a $59 million economic contribution to the state of Minnesota in 2011 (Tuck and Gartner 2013), it is imperative that we determine how SWD phenology and biology impacts production of cold hardy grapes in Minnesota. The results that are generated through this project will provide the basis for an effective Integrated Pest Management (IPM) program for the industry.


With more than 1,000 acres of grapes grown in Minnesota (USDA NASS 2012), and insects and diseases ranking as the top two production challenges for growers (Tuck and Gartner 2013), it is critical that we support the industry with IPM solutions for new invasive insect pests. The invasive SWD, Drosophila suzukii, first detected in Minnesota in 2012, has been a recurring problem for late fall ripening fruit crops – particularly for grapes in 2016 (Clark et al. 2016). Despite the availability of insecticides for small fruit crops, reducing infestations to acceptable (marketable) levels continues to be a challenge (Rogers et al. 2016), and virtually no research on SWD management is available for wine grapes in the Midwest region. To date, SWD research in Minnesota grapes has been limited to monitoring adult flies in selected vineyards, with very little work done to understand the risk and damage of SWD to grapes, contaminant concerns during processing and final wine quality. Consequently, few IPM solutions are available (Asplen et al. 2015; MN IPM Program; In addition to the direct risk of SWD to wine grapes in the field (egg and/or maggot infestations in fruit or juice, Fig. 1b), fly activity within vineyard buildings is also a growing concern due to the possible contaminant impacts of acetic acid bacteria (AAB) and sour rot [Bartowsky & Henschke (2008), Baratta et al. (2012)]. Given our previous work with SWD and knowledge of grape/wine production (e.g., Galvan et al. 2008), this has become one of the most challenging invasive pests to impact MN grape growers over the past 40 years. In collaboration with leading growers in Minnesota, we propose the following research to develop an effective IPM program.


  1. Determine season-long phenology of SWD in grapes in MN with an early-detection Scentry™ Trap and Lure system (Hastings vineyard and UMN, HRC)
  2. Use Scentry traps and Exclusion netting in winery (fermentation) buildings to minimize the risk of SWD as a contaminant during processing
  3. Conduct on-farm research to assess the efficacy and logistics of using exclusion netting for control of SWD (Hastings), including: Exclusion netting coupled with SWD traps, Exclusion netting alone, Non-exclusion (open field) insecticide treatment, and Non-exclusion untreated check (randomized complete block design)
  4. Compare MN cold hardy & selected European germplasm for field susceptibility to SWD field infestation levels (Hastings vineyard, and Landscape Arboretum grape breeding area, HRC); selected varieties will be evaluated in the Entomology laboratory using known adult infestation levels (via access to the SWD colony maintained in Hutchison lab)
  5. Evaluate the impact of known SWD infestation levels (adults/maggots) in berries and juice on key quality parameters, including: Brix, acidity, acetic acid bacteria (AAB) levels, that may affect wine quality (UMN Enology Lab), for ~20 cold hardy grape varieties; the quality parameters will also be examined for correlation to physical characteristics and cluster architecture, such as berry skin thickness (via penetrometer) and cluster size and tightness.


Asplen M.K., G. Anfora, A. Biondi, D-S Choi, D. Chu, K.M. Daane, P. Gibert, A.P. Gutierrez, K.M. Hoelmer, W.D. Hutchison, R. Isaacs, Z-L Jiang, et al. 2015.

Invasion biology of spotted wing Drosophila (Drosophila suzukii): A global perspective and future priorities. J Pest Sci. 88(3): 469-494. Barata, A., S.C. Santos, M. Malfeito-Ferreira, and V. Loureiro. 2012.

New insights into the ecological interaction between grape berry microorganisms and Drosophila flies during development of sour rot. Microb. Ecol. 64: 416-430. Bartowsky, E.J. and P.A. Henschke. 2008.

Acetic acid bacteria spoilage of bottled red wine—A review. Intern. J. of Food Microbiol. 125: 60-70. 5 Clark, M., E.C. Burkness, D. Horton & B. Hutchison. 2016.

SWD Concern in Grapes. Pest Alert to Growers, Sept. 27th.

FruitEdge, UMN Extension (on-line): Galvan, T.L., R.L. Koch, & W.D. Hutchison. 2008.

Potential implications of fruit feeding on overwintering survival of the multicolored Asian lady beetle, and the ability for these insects and paper wasps to injure wine grape berries. Entomol. Applic. 128: 429-436. Ioratti C., V. Walton, D. Dalton, G. Anfora, A. Grassi, S. Maistri, & V. Mazzoni. 2015.

Drosophila suzukii (Diptera: Drosophilidae) and its potential impact to wine grapes during harvest in two cool climate wine grape production regions. J. Econ. Entomol. 108: 1148-1155. Leach, H., S. Van Timmeren, & R. Isaacs. 2016.

Exclusion netting delays and reduces Drosophila suzukii (Diptera: Drosophilidae) infestation in raspberries. J. Econ. Entomol. 109(5): 2151-2158. Rogers, M.A., E.C. Burkness, & W.D. Hutchison. 2016.

Evaluation of high tunnels for management of Drosophila suzukii in fall-bearing red raspberries: Potential for reduced use of insecticides.J. Pest Sci. 89(3): 815-821. Tuck, B. & W. Gartner. 2013.

Vineyards and Wineries in Minnesota, a status and economic contribution report. USDA NASS. 2012.

2012 Census of Agriculture – State Data.