WERA1021: Spotted Wing Drosophila Biology, Ecology, and Management

(Multistate Research Coordinating Committee and Information Exchange Group)

Status: Inactive/Terminating

WERA1021: Spotted Wing Drosophila Biology, Ecology, and Management

Duration: 10/01/2017 to 09/30/2022

Administrative Advisor(s):

NIFA Reps:

Statement of Issues and Justification

Spotted wing drosophila (SWD, Drosophila suzukii) has rapidly expanded its global range in the last eight years. Native to eastern Asia, it is now found in the United States, Canada, Mexico, Europe, and most recently South America (Walsh et al. 2011, Asplen et al. 2015). SWD is a destructive pest of soft skinned fruit including blueberries, blackberries, cherries, raspberries, and strawberries, which have an aggregate annual value of over $4.37 billion (USDA NASS 2013), and national crop loss due to SWD has been estimated at up to $718 million annually (eFly Working Group 2012). Female SWD use a saw-like ovipositor to penetrate the skin of ripe or unripe fruit, attacking a broad range of hosts, including both cultivated and uncultivated plant species (Lee et al. 2011, Walsh et al. 2011). This, coupled with the exceptionally high reproductive capacity of this pest (Emiljanowicz et al. 2014), makes it extremely difficult to manage. In some regions of the U.S., a zero tolerance policy for SWD results in complete rejection of fruit if even a single larva is detected in a shipment. Therefore, very conservative management strategies, such as weekly applications of broad-spectrum insecticides when fruit are ripe (Diepenbrock et al. 2016), are employed. Indeed, fruit growers reported increases in pesticide costs of between $100-300 per acre due to SWD (eFly Working Group 2014). This is not an economically feasible management strategy for many farmers, and has dramatically impacted the sustainability of soft-skinned fruit production. Alternative management strategies are desperately needed. Multiple cropping systems and climatic regions are impacted by SWD, and given the severity and scope of losses due to SWD, a multi-state approach is warranted. 

SWD is a top research priority for national, regional, and state grower organizations. All recently updated Pest Management Strategic Plans (PMSPs) for soft skinned fruits consider SWD a research and extension priority. Therefore, research funding (USDA-SCRI, USDA-OREI, USDA Specialty Crop Block Grant, regional IPM centers, grower funding, etc.) has been obtained to study SWD in many regions of the U.S. The purpose of this committee is to foster and facilitate information exchange to ensure that research, extension, and outreach efforts are appropriate, regionally relevant, and disseminated to stakeholders in a timely manner while minimizing redundant efforts. In addition, this committee facilitates the development of new Multi-State and regional research and Extension projects by fostering collaboration and communication among researchers and Extension agents from multiple organizations. Such efforts have enabled members of this group to obtain funding for such projects. This collaboration will support fruit growers, packers, processors, marketers, export agencies, extension personnel, and fruit consumers by helping the production of healthful soft-skinned fruits in an economically and environmentally sustainable way. Stakeholders are regularly engaged in assessing the value of the research, education, and extension efforts of the Coordinating Committee.


  1. Improve our understanding of SWD populations and develop tools to accurately predict SWD risk.
  2. Optimize use of pesticides to reduce reliance upon them and disruption of beneficials.
  3. Develop non pesticide based tactics for SWD management and evaluate sustainable SWD management programs to provide best management practices for SWD.
  4. Coordinate grant-funded research and extension efforts to minimize redundancy and ensure knowledge transfer.

Procedures and Activities

Objective 1: Improve our understanding of SWD populations and develop tools to accurately predict SWD risk. Reliable monitoring of pest populations, ensuring control measures are not taken needlessly, is essential for sustainable pest management. Not only can SWD use a broad range of resources, including many non-crop hosts (Lee et al. 2015), but they also have high reproductive capacity (Emiljanowicz et al. 2014), and develop relatively rapidly (Tochen et al. 2014). Populations build rapidly with generations overlapping early in the season, and current monitoring tools are limited in their ability to predict SWD damage. We will address these knowledge gaps with coordinated multi-state research. To improve our ability to model SWD populations nationally, we will compare regional data on SWD trap captures, infestation, and weather across different host crops and conduct studies to refine population models. SWD may be moving at local and regional scales between habitats. Molecular tools will be developed that allow for differentiation between long range and local dispersal. Experiments will be conducted to track SWD movement and infestation across hosts, determining seasonal, temporal, and spatial usage of and dispersal among crops and non-crop hosts. We will coordinate efforts to develop monitoring tools that accurately estimate SWD populations including studies to improve our understanding of currently available attractants, develop and optimize new attractants, and time treatments based on trap captures. Specifically, the range of attraction, efficiency of attractants, impact of background volatiles, and role of physiological state will be evaluated for their impact on SWD’s response to attractants. 

Objective 2: Optimize use of insecticides to reduce reliance upon them and disruption of beneficials. Stakeholders regularly prioritize research to optimize use of insecticides because current spray programs may not meet their management goals and insecticide resistance is a concern. Regional production practices and climatic factors such as rainfall impact efficacy, necessitating multi-state research projects. We will evaluate various spray adjuvants to improve rainfastness and efficacy.  Standard methodologies to evaluate insecticide resistance in the field will be developed and used to monitor resistance nationally. To minimize disruption of beneficials, the impact of adjuvants and insecticides on non-target biological control agents and other beneficials will also be evaluated. 

Objective 3: Develop non pesticide based tactics for SWD management and evaluate sustainable SWD management programs to provide best management practices for SWD. Currently, both organic and conventional production systems rely heavily upon chemical control tactics to manage SWD, and additional management tactics are desperately needed. Regional differences in production practices impact the efficacy and feasibility of management tactics; therefore, a multi-state approach is warranted. Tactics will be evaluated first in laboratory, small plot, and localized experiments. The most promising approaches will then be evaluated in coordinated regional field trials to evaluate their efficacy under a range of climatic and production conditions. Cooperating with stakeholders in each region, replicated, on-farm research will be performed to evaluate new management tactics for SWD and encourage adoption of IPM programs. Economic analyses of specific management practices and bioeconomic models to identify profit maximizing management strategies will be used to generate research-based recommendations and decision support tools. 

Objective 4: Coordinate grant-funded research and extension efforts to minimize redundancy and ensure knowledge transfer. Because SWD is an economically significant threat nationally, many individuals are performing research, extension and outreach efforts. This committee will enhance collaborations and provide opportunities to share information and ideas, facilitating needs assessments, minimizing redundancy, and accelerating delivery of outputs to stakeholders.

Expected Outcomes and Impacts

  • 1. This project will coordinate research and extension efforts, allowing for the exchange of ideas, information, and data thereby accelerating SWD research and extension throughout the U.S. This committee has facilitated the development and funding of multiple Multi-State projects and we anticipate that future regional and Multi-State projects will result from this coordination.
  • 2. Regionally appropriate decision support tools will be developed and disseminated to stakeholders, resulting in economic benefits due to improved decision making. This committee will enable the development and dissemination of improved monitoring and thresholds for spotted wing drosophila, which will allow for judicious use of chemical control strategies and decrease insecticide use for spotted wing drosophila management.
  • 3. Regionally appropriate IPM programs will be developed and disseminated to stakeholders, resulting in economic benefits due to improved management tactics and decision-making. Specifically, members of this team are developing tactics that will be incorporated into IPM programs such as cultural control methods, attract and kill strategies, exclusion approaches and optimized chemical control. The adoption of best management practices for spotted wing drosophila will decrease yield losses, increase profitability, and improve sustainability.
  • 4. Committee participants will produce complementary and collaborative research articles, reducing duplication of efforts while providing timely research-based information and educational materials to research and Extension teams nationally. These efforts will increase the dissemination of information and ensure that stakeholders gain the knowledge and skills they need to successfully manage spotted wing drosophila.
  • 5. Timely communication to stakeholders will allow growers and industries to mitigate the impact of SWD-related crop losses and will result in more environmentally and economically sustainable fruit production in the USA. The efforts of this committee will increase the adoption of best management practices and IPM approaches for managing spotted wing drosophila.

Projected Participation

View Appendix E: Participation

Educational Plan

At each annual meeting, the committee will present the current year's activities, and then discuss, share and coordinate SWD management issues, future research and extension needs, extension educational approaches, and novel applications within regional fruit production and home gardener/urban landscape systems. The annual meeting will provide a forum for research and extension liaisons throughout the country to discuss issues and coordinate responses. An annual report will be compiled to provide documentation of regional deliverables and accomplishments in SWD management during the past year. Following the annual meeting, members of the committee will disseminate information gained to appropriate parties within their areas. Extension agents and teams will be updated and trained as needed, workshops and field days will be organized, and educational materials will be shared with grower groups. Throughout the year, members of the committee will share information with each other about what outreach materials and approaches were most and least effective. 

During this project, WERA members will organize at least one regional symposium at a branch meeting of the Entomological Society of America, a national symposium at an Annual Meeting of the Entomological Society of America, and at the International Congress of Entomology meeting in 2020 (Finland). These professional activities will: 1) expand information exchange beyond the WERA membership, 2) address specific learning needs, 3) provide professional development to stakeholders, 4) foster inter-agency and regional/national linkages, dialogue, learning and information dissemination, with an emphasis on designing and implementing sustainable management of SWD. Stakeholder involvement will be strongly encouraged.


Officers include a chair, a past-chair, and vice-chair (chair-elect) who will record meeting minutes, maintain a current email list, and maintain contact with the administrative adviser. Election of a new vice-chair occurs at each annual meeting, and this new officer is installed immediately. It is the responsibility of the current chair to organize and host the annual meeting. Because a primary objective of this committee is to foster interdisciplinary research and extension involving SWD, officers and members encourage the Directors from each state to sponsor at least two professionals to attend the annual meetings as voting members. The committee desires both Experiment Station and Extension representation. Additional participants are welcome.

Literature Cited

Asplen, M.K., Anfora, G., Biondi, A., Choi, D.S., Chu, D., Daane, K.M., Gibert, P., Gutierrez, A.P., Hoelmer, K.A., Hutchinson, W.D., Isaacs, R., Jiang, Z.-L., Kárpáti, Z., Kimura, M.T., Pascual, M., Philips, C.R., Plantamp, C., Ponti, L., Vétek, G., Vogt, H., Walton, V.M., Yu, Y., Zappalà, L., and N. Desneux. 2015. Invasion biology of spotted wing drosophila (Drosophila suzukii): a global perspective and future priorities. J. Pest Sci. 88:469-494.

Diepenbrock, L.M., Olivieri Rosensteel, D., Hardin, J.A., Sial, A.A., and H.J. Burrack. 2016. Season-long programs for control of Drosophila suzukii in southeastern U.S. blueberries. Crop Prot. 81: 76-84.  

eFly Working Group. 2012. Spotted wing drosophila impact statement. https://swd.ces.ncsu.edu/eastern-us-swd-impacts/, accessed 10/31/15.

eFly Working Group. 2014. Spotted wing drosophila impact statement. https://swd.ces.ncsu.edu/swd-impacts-2014/, accessed 10/31/15.

Emiljanowicz, L.M., Ryan, G.D., Langille, A., and J. Newman. 2014. Development, reproductive output and population growth of the fruit fly pest Drosophila suzukii (Diptera: Drosophilidae) on artificial diet. J. Econ. Entomol. 107(4): 1392-1398.

Lee, J.C., Dreves, A.J., Cave, A.M., Kawai, S., Isaacs, R., Miller, J.C., Van Timmeren, S., and D.J. Bruck. 2015. Infestation of wild and ornamental noncrop fruits by Drosophila suzukii (Diptera: Drosophilidae). Ann. Entomol. Soc. Am. 108(2):117-129.

Tochen, S., Dalton, D.T., Wiman, N., Hamm, C., Shearer, P.W., and V.M. Walton. 2014. Temperature-related development and population parameters for Drosophila suzukii (Diptera:Drosophilidae) on cherry and blueberry. Environ. Entomol. 43: 501-510.

USDA NASS. 2013. Agricultural statistics data base, www.nass.usda.gov, accessed 3/31/2015.

Walsh, D.B., Bolda, M.P., Goodhue, R.E., Dreves, A.J., Bruck, D.J., Walton, V.M., O’Neal, S.D., and F.G. Zalom. 2011. Drosophila suzukii (Diptera: Drosophilidae): invasive pest of ripening soft fruit expanding its geographic range and damage potential. J. Integr. Pest Manag. 2: 1-7.


Land Grant Participating States/Institutions


Non Land Grant Participating States/Institutions

Metro State University, USDA-ARS/Oregon, USDA-ARS/Washington
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