Pollination of Wisconsin cucumber: The impact of landscape on native bee population

The reproductive ability and fruit development of cucurbits are dependent upon insect-mediated pollination. Native bees have the potential to provide complete or considerable contribution towards pollination of crops that have traditionally relied on managed pollinators. We addressed the scarcity of information regarding native pollinators of pickling cucumber, and sampled the native bee community over a two year period in Central Wisconsin. Eighteen fields planted between May and July were examined for the presence of native bees prior to bloom, after first flowering, and during peak bloom. GIS analyses of the land cover within 500-2000 m buffers of sites were used to predict if surrounding landscape influences the abundance and species diversity of native bees. Over 2000 bees from 45 species were collected during this survey. At the local and landscape level, bee abundance was positively related with natural area adjacent to fields, only during bloom. The presence of certain species fluctuated throughout the season, with cucurbit specialists from Xenoglossa and Peponapis observed foraging. Bee abundance was similar at all sites before bloom, indicating that remnants of natural area could be essential to pollinators. Most large-scale cucumber growers in Wisconsin rely exclusively on Honey bees, and the data suggest that there could be opportunities to utilize the incidental pollination services of native pollinators. Further work will be needed to determine if habitat restoration efforts can enhance the levels of pollinators at risk from agricultural intensification.