The impact of floral diversity on bumblebee colony development and pollination efficacy among foragers

The environment in which pollinators are reared may influence both their health and pollination performance. We compared the performance of 12 colonies of bumblebees (Bombus terrestris), each in their own simple (tomato monoculture) or florally diverse (tomatoes, borage, and lavender) arena inside a glasshouse. We found that colonies reared in florally diverse environments had a higher proportion of foragers overall and maintained slightly higher and less variable relative humidity inside the nest. Moreover, adding floral resources to a tomato crop resulted in increased total crop yield, whereas individual tomatoes reared in the simple monoculture environment were larger than those in the diverse. These results provide an important step in understanding the extent to which bumblebee health and flower-visiting behavior are influenced by the complexity of the foraging environment and how a diverse floral environment may enhance pollinator behavior toward a focal crop.