Efficacy of biopesticides on spotted wing drosophila, Drosophila suzukii Matsumura in fall red raspberries

et al. 2019

Self Cite

Spotted‐wing drosophila, Drosophila suzukii (Matsumura), is an invasive pest affecting fruit production in many regions of the world. Insecticides are the primary tactic for controlling D. suzukii in organic as well as conventional production systems. Organic growers have a greater challenge because fewer insecticides are approved for use in organic agriculture. The most effective organically approved product is spinosad, but alternatives are needed because of label restrictions limiting the number of applications per year, toxicity to beneficial arthropods and the risk of developing resistance. We evaluated several organically approved insecticides against D. suzukii in laboratory assays and field trials conducted on organic blueberry and raspberry farms. Spinosad was consistently the most effective insecticide, but a few other insecticides such as azadirachtin + pyrethrins, Chromobacterium subtsugae and sabadilla alkaloids showed moderate activity. None of the treatments had long residual activity. Mortality started to decline by 3 days after treatment, and by 5 days after application, the treatments were not different from the controls. These products may be useful in rotation programmes, necessary for reducing reliance on spinosad and mitigating resistance. Cultural and biological control approaches are needed in fruit production for D. suzukii management, but insecticides will likely continue to be the dominant management tactic while these other approaches are being optimized and adopted.

mentioning

confidence: 99%

Evaluation of organic insecticides for management of spotted‐wing drosophila (Drosophila suzukii) in berry crops

Sial

et al. 2019

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“…Spinosad has proven effective in multiple studies and is one of the main products used in organic D. suzukii chemical control programmes (Beers et al, 2011;Bruck et al, 2011;Cahenzli et al, 2018;Van Timmeren & Isaacs, 2013). Other biopesticides that showed efficacy in some of our experiments and in other studies included azadirachtin, C. subtsugae, pyrethrins and sabadilla alkaloids (Fanning et al, 2018;Iglesias & Liburd, 2017;Shawer, Tonina, Tirello, Duso, & Mori, 2018). However, these other studies also noted the short residual activity of these products and recommended using them in rotation with spinosad.…”

Section: Discussionmentioning

confidence: 59%

Impact of phagostimulants on effectiveness of OMRI‐listed insecticides used for control of spotted‐wing drosophila (Drosophila suzukii Matsumura)

Fanning

et al. 2019

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Spotted‐wing drosophila, Drosophila suzukii Matsumura, is an invasive pest in the United States that causes considerable damage to fruit crops. It is responsible for many millions of dollars of revenue loss. The female D. suzukii has a heavily sclerotized ovipositor and can lay eggs in ripening or ripe fruit. The arrival of this invasive species has disrupted existing integrated pest management programmes, and growers rely on repeated insecticide applications to protect fruit. Organic growers have few chemical control options, and their reliance on spinosad increases the risk of developing insecticide resistance. We hypothesized that combining phagostimulants with insecticides would increase insecticide efficacy by prompting flies to spend more time in contact with residues. Therefore, the objective of this study was to evaluate the effectiveness of sucrose and the yeast Saccharomyces cerevisiae as phagostimulants in combination with organic biopesticides against D. suzukii in blueberries. Adding sucrose with or without yeast did not improve insecticide efficacy in terms of adult fly mortality or fruit infestation. Spinosad was very effective in all experiments, and for this product, there is little room for improvement. The phagostimulants had no effect on residual activity of any insecticide. The addition of sucrose with or without yeast did not improve the effectiveness of organic insecticides for D. suzukii. Concentrations of these phagostimulants in our experiments (0.36%) may have been too low to elicit a response. Further research is recommended to test different types and concentrations of phagostimulants.

“…A reduction in sensitivity to a spinosyn class insecticide has already been reported (Gress & Zalom, ; Van Timmeren, Mota‐Sanchez, Wise, & Isaacs, ). Several National Organic Program (NOP)—compliant insecticides have recently been evaluated in a series of laboratory and semi‐field experiments (Fanning, Grieshop, & Isaacs, ; Guédot & Perry, ; Iglesias & Liburd, ; Van Timmeren & Isaacs, ; Wise, VanWoerkom, & Isaacs, ). These products included biopesticides representing various modes of action.…”

Section: Introductionmentioning

confidence: 99%

“…Gautam et al () and Wise et al () used P1M in their experiments, but most insecticide studies targeting D. suzukii have not included adjuvants. Fanning et al () used eight adjuvants including PEPMS in their study, but they only tested these in combination with a single product. Effective adjuvants could expand the number of useful insecticide options for D. suzukii management in organic berry crops.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of adjuvants to improve control of spotted‐wing drosophila in organic fruit production

Fanning

et al. 2019

Self Cite

Spotted‐wing drosophila, Drosophila suzukii (Matsumura), is a key pest of berry crops in the United States. It is managed intensively using insecticides, but organic fruit growers have few effective chemical control options. Spinosad is the most effective organically approved product for control of D. suzukii, while other organic options have not shown high levels of control. Adjuvants are products added to pesticides to improve effectiveness, and these may function as stickers, spreaders or surfactants improving the spray coverage of insecticides on surfaces and thereby increasing the likelihood that pests will contact residues. We conducted experiments evaluating organically approved biopesticides in combination with three adjuvants including poly‐1‐p‐menthene, alcohol ethoxylate and polyether‐polymethylsiloxane‐copolymer polyether to determine whether addition of adjuvants improved efficacy and residual activity of these products. Alcohol ethoxylate and poly‐1‐p‐menthene showed some inherent insecticidal activity against D. suzukii in laboratory assays. Adjuvants increased mortality of some insecticides but not to a level that would provide adequate fruit protection. Poly‐1‐p‐menthene had a negative effect when combined with hydrogen peroxide + PAA and sabadilla alkaloids. Mortality in semi‐field bioassays was quite low except for spinosad. Polyether‐polymethylsiloxane‐copolymer polyether had a negative effect on the efficacy of spinosad. The adjuvants did not extend residual activity of the insecticides. Adjuvants did not provide the expected benefits of increased performance against D. suzukii when combined with organic biopesticides. Other methods for enhancing these insecticides will need to be explored to provide organic growers with more effective chemical control options for this invasive pest.