Evaluation of a push-pull strategy for Spotted-wing Drosophila management in Highbush Blueberry Orchard

Authors: GALE, CODY - ARS Postdoctoral Research Associate; FERGUSON, BETH - Rutgers University; RODRIGUEZ-SAONA, CESAR - Rutgers University; SHIELDS, VONNIE - Towson University; Zhang, Aijun

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/8/2024
Publication Date: 1/10/2024
Citation: Gale, C., Ferguson, B., Rodriguez-Saona, C., Shields, V.D., Zhang, A. 2024. Evaluation of a push-pull strategy for Spotted-wing Drosophila management in Highbush Blueberry Orchard. Insects. https://doi.org/10.3390/insects15010047.
DOI: https://doi.org/10.3390/insects15010047

Interpretive Summary: The spotted-wing drosophila (SWD) is an invasive pest of soft-skinned fruits that has rapidly spread across the globe and causes hundreds of millions of dollars in crop losses worldwide. Today, management of SWD is heavily relied on the application of synthetic pesticides, which are potentially hazardous to humans, animals, other organisms, and the environment. Natural product based sustainable integrated pest management approach is urgently needed to reduce conventional synthetic pesticide usages. A promising behavior-based control method is the “push-pull” strategy which uses a repellent to drive pests away from fruits (push) and towards SWD attractant-baited mass trapping devices (pull). Methyl benzoate, a naturally occurring chemical found in many plants and FDA approved food additive, was found to be repellent to spotted-wing drosophila in laboratory tests, so in this study we evaluated whether this compound could also be used to protect blueberries from spotted-wing drosophila injury in the field. Our results demonstrated that methyl benzoate as a spatial repellent/deterrent can be deployed by in blueberry fields to reduce damage caused by spotted-wing drosophila. Growers can use this strategy as alternative to synthetic pesticide for organic farming.

Technical Abstract: We evaluated a novel push-pull control strategy for protecting highbush blueberry, Vaccinium corymbosum, against spotted-wing drosophila (SWD), Drosophila suzukii. Methyl benzoate (MB) was used as the pushing agent and a previously-tested SWD attractive blend of lure-scents as the pulling agent. MB dispensers (push) were hung in the canopy and lure-scent dispensers (pull) were hung in yellow jacket traps filled with soapy water around the blueberry bushes. Blueberries were sampled weekly and infestation was inspected by examining the breathing tubes of SWD eggs which protrude through the skin of infested fruit. Overall, the frequency of infestation, i.e., the proportion of berries infested with at least one egg, and the extent of infestation, i.e., the mean number of eggs in infested berries, were significantly reduced in treatments receiving MB dispensers as a pushing agent. The protection of blueberry provided by the MB dispensers was more apparent in field tests with higher SWD pest pressure. However, the mass trapping devices as a pulling agent did not provide considerable protection on their own and did not produce additive protection when used in combination with the MB dispensers in push – push trials. We conclude that MB has the potential to be implemented as a spatial repellent/oviposition deterrent to reduce SWD damage in blueberry under field conditions and a push-pull strategy that employs in our trials does not require the SWD attractant as a pulling agent to achieve crop protection, especially, in low SWD pest pressure.