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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #317142
Title: Reduced spray programs for Drosophila suzukii management in berry crops

Author
item KLICK, JIMMY - Oregon State University
item YANG, WEI - Oregon State University
item Lee, Jana
item BRUCK, DENNY - Pioneer Hi-Bred International

Submitted to: International Journal of Pest Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/27/2016
Publication Date: 9/2/2016
Citation: Klick, J., Yang, W., Lee, J.C., Bruck, D. 2016. Reduced spray programs for Drosophila suzukii management in berry crops. International Journal of Pest Management. 62(4):368-377: doi: 10.1080/09670874.2016.1222105.

Interpretive Summary: The arrival of spotted wing drosophila (SWD) has led to increased numbers of field applications of broad-spectrum insecticides to protect susceptible fruit from infestation in berry crop production. Field studies were conducted from 2011 to 2013 to determine whether reduced spray treatments in the form of spraying every alternate row, or the borders could manage SWD as well as complete sprays and have less of an impact on non target arthropods. Four raspberry sites and one blueberry site were alternate row middle and border sprayed, respectively. Captures of SWD were compared to conventional complete spray programs. Non-target arthropods were evaluated 7 d post-harvest. In both reduced spray trials, no differences in mean adult numbers and larvae of SWD were detected between treatments. Mean counts immediately after sprays (i.e., 3 – 12 d after treatment) were also similar in complete and alternate row sprays. Both reduced spray strategies had significantly more lady beetles that feed on pest mites.; additionally, alternate row sprays had significantly more fungal feeding lady beetles. No difference in fruit knockdown by complete or border spray was observed. These reduced pesticide strategies are additional tools to consider in SWD IPM programs that reduce amount of spray area, application time, and input costs while conserving natural enemies.

Technical Abstract: BACKGROUND: Since the arrival of Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), field applications of broad-spectrum insecticides have significantly increased to protect susceptible fruit from infestation in berry crop production. Field studies were conducted from 2011 to 2013 to determine whether alternate row middle or border treated reduced spray programs could manage D. suzukii as well as complete sprays and have less of an impact on non target arthropods. Four raspberry sites and one blueberry site were alternate row middle and border sprayed, respectively. Captures of D. suzukii were compared to conventional complete spray programs. Non-target arthropods were evaluated 7 d post-harvest. RESULTS: In both reduced spray trials, no differences in mean adult numbers and larvae of D. suzukii were detected between treatments. Mean counts immediately after sprays (i.e., 3 – 12 d after treatment) were also similar in complete and alternate row sprays. Both reduced spray strategies had significantly more Stethorus spp.; additionally, alternate row sprays had significantly more Psyllobora spp. No difference in fruit knockdown by complete or border spray was observed. CONCLUSION: These reduced pesticide strategies are additional tools to consider in D. suzukii IPM programs that reduce amount of spray area, application time, and input costs while conserving natural enemies.