Bee nutrition and floral resource restoration: Integrating nutritional ecology and conservation

Agricultural intensification has contributed to pollinator population declines, in part by reducing bee host-plant species abundance and diversity. The worldwide concern for conservation of bee pollination services has lead to interest in habitat or floral restoration protocols to support pollinator populations in agricultural landscapes. Because bees rely entirely on floral rewards for nutrition and nutritional quality of nectar and pollen vary among plant species, bees may be experiencing nutritional stress in landscapes with reduced floral diversity. Therefore, to nutritionally support bee populations, there is a need to understand bee foraging behavior, host-plant species choice, how foraging decisions relate to their nutritional needs, and to determine if bee nutritional requirements are met in altered landscapes. Here, we present our recent research on pollen foraging behavior and nutrition for Bombus impatiens (Common Eastern Bumble Bee). We evaluated the influence of nutritional quality on pollen species preferences for B. impatiens, as well as their ability to regulate intake of carbohydrate, protein, and lipid macronutrients. We also explored landscape-level effects of pollen diversity and nutrition on colony health. By integrating results from these studies, we may improve selection of host-plant species for designing nutritionally optimized floral restoration and a framework in which to test the nutritional ecology of other bee species. We emphasize that floral-species and nutritional diversity are vital for meeting the requirements for survival and reproduction of multiple bee species while maximizing their resilience to stress.