Impacts of semi-natural habitat restoration in agroecosystems on pest and beneficial insect biodiversity

Semi-natural habitat restoration is a potential tool for growers to support the biodiversity of beneficial insects. These insects provide sustainable population control of numerous pest insect species important to agriculture. One pest of particular interest in British Columbia is the spotted wing Drosophila, an invasive fruit fly that causes extensive damage to berries and soft fruits in the region. Recently, two species of exotic parasitoid wasp that target the spotted wing Drosophila were found to have established in British Columbia. Understanding the effects of these parasitoids on spotted wing Drosophila will be important to their population management in the coming years. We studied the effects of habitat enhancements, like grassland set-asides and hedgerows, on pest and beneficial insect biodiversity, with a focus on spotted wing Drosophila and its parasitoids, on 28 field sites in Delta, British Columbia, Canada. Sampling was conducted during the summers of 2020 and 2021. Vegetation surveys were also conducted on study sites to control for plant composition effects. Insect samples from the 2020 season are in the process of being identified and will subsequently be analyzed for trends in biodiversity and abundance. Initial findings indicate that spotted wing drosophila makes use of wild blackberries as a host on farmlands, and that at least one of the two exotic parasitoid species has established in the Delta region.