The effects of Indigenous intercropping on pollinator visitation and floral volatiles in Cucurbita pepo

The ongoing decline of pollinators due to multiple stressors underscores the importance of integrating pollinator conservation into agricultural system management. One example of a sustainable and productive agroecosystem is an Indigenous planting system known as the Three Sisters: corn (Zea mays), beans (Phaseolus vulgaris), and squash (Cucurbita pepo). In comparison with a squash monoculture, three Sisters polycultures have more abundant and diverse floral resources. Previous research has shown that intercropping beans with squash increases bee abundance and diversity, but the mechanisms underlying this difference are still unknown. Plants have been shown to emit significantly different volatile profiles when grown in close association with heterospecific vs. conspecifics, so it is possible that the floral volatile profile emitted by squash flowers in monoculture may differ from that of polyculture. In a field experiment, we planted plots of Three Sisters and squash monocultures to test the hypothesis that the presence of multiple plant species will attract a more diverse and abundant pollinator community. We expect that squash flowers in polycultures will be more frequently visited by bees compared to squash flowers in monoculture, partially due to differences in floral volatile composition. We also expect that the bee community will be more taxonomically diverse within the polyculture plots due to the presence of multiple floral resources. This study will be the first to directly quantify the pollinator community associated with the Three Sisters agricultural approach and will improve our understanding of the ecological dynamics of intercropping for pollinator-friendly management strategies.