Nonnutritive sugars for spotted-wing drosophila (Diptera: Drosophilidae) control have minimal nontarget effects on honey bee larvae, a pupal parasitoid, and yellow jackets

Authors: Price, Briana; BREECE, CAROLYN - Oregon State University; Galindo, Gracie; GREENHALGH, ABIGAIL - Oregon State University; SAGILI, RAMESH - Oregon State University; Choi, Man-Yeon; Lee, Jana

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/19/2022
Publication Date: 11/16/2022
Citation: Price, B.E., Breece, C., Galindo, G., Greenhalgh, A., Sagili, R., Choi, M.Y., Lee, J.C. 2022. Nonnutritive sugars for spotted-wing drosophila (Diptera: Drosophilidae) control have minimal nontarget effects on honey bee larvae, a pupal parasitoid, and yellow jackets. Environmental Entomology. 52(1):47-55. https://doi.org/10.1093/ee/nvac095.
DOI: https://doi.org/10.1093/ee/nvac095

Interpretive Summary: The spotted-wing drosophila (SWD), a major pest of small fruits and cherries is often managed with conventional insecticides. Our previous work found that erythritol, a sugar substitute, is toxic to SWD. Two mixtures of erythritol (1.5 M), with either 0.5 M sucrose or 0.1 M sucralose, effectively kill SWD. In this study, we investigated whether these mixtures affect honey bee larvae, a parasitic wasp that attacks SWD pupae, and western yellow jacket. We directly exposed honey bee larvae to formulations by adding a high dose to larval cells and found no significant mortality from either formulation compared to the water control. The parasitic wasp may encounter erythritol in field settings when plants are sprayed. The erythritol+sucralose mixture is more detrimental than erythritol+sucrose to the wasp. However, this effect was greatly reduced within a 21-d period when other sugar foods such as floral nectar are available. Since yellow jackets are a nuisance pest and were attracted to the erythritol formulations in recent field trials, we tested adult survival in a laboratory setting and found no detectable detriment from either mixture, compared to sucrose control. Overall, our results indicate that both erythritol formulations cause minimal non-target effects to honey bee larvae, a parasitic wasp, and western yellow jacket.

Technical Abstract: Drosophila suzukii Matsumura, spotted-wing drosophila, a major pest of small fruits and cherries is often managed with conventional insecticides. Our previous work found that erythritol, a non-nutritive polyol, has insecticidal properties to D. suzukii. Two formulations of erythritol (1.5 M), with 0.5 M sucrose or 0.1 M sucralose, are most effective at killing D. suzukii in various tests. In this study, we investigate non-target effects of these erythritol formulations to honey bee Apis mellifera Linnaeus larvae, a pupal parasitoid of D. suzukii, Pachycrepoideus vindemiae Rondani, and western yellow jacket, Vespula pensylvanica Saussure. We directly exposed honey bee larvae to these erythritol formulations by adding a high dose (2 µl) to larval cells and found no significant mortality from either formulation compared to the water control. Pachycrepoideus vindemiae may encounter erythritol in field settings when host plants of D. suzukii are sprayed. Our laboratory results indicate that the erythritol+sucralose formulation is more detrimental than erythritol+sucrose to P. vindemiae, however, this effect is greatly reduced within a 21-d period when a floral source is present. Since yellow jackets are a nuisance pest and were attracted to the erythritol formulations in recent field trials, we tested adult V. pensylvanica survival with continuous consumption of these formulations in a laboratory setting and found no detectable detriment from either formulation, compared to sucrose control. Overall, our results indicate that both erythritol formulations cause minimal non-target effects to the honey bee larvae, D. suzukii parasitoid, and western yellow jacket.