| dc.description.abstract | Inadequate nutrition, particularly in terms of pollen acquisition, has been attributed as one of the primary reasons for poor honey bee (Apis mellifera) colony health. This can be due to changes in the landscape and the loss of local floral diversity negatively affecting the quantity and quality of pollen that foragers bring back to the hive. In addition, many of the artificial protein diets used to supplement colony nutrition are suboptimal and ineffective compared to natural pollen. Despite knowing what resources bees collect, there is still a knowledge gap on the colonies’ dietary needs because of the complexity of pollen. Therefore, there is not, at present, an ideal substitute for pollen that beekeepers can readily apply in times of resource dearth. This dissertation is focused on identifying honey bee pollen foraging preferences to better understand their dietary needs. To address this topic, I performed a series of experiments that allow me to make inferences on the nutritional basis for honey bee pollen foraging preferences.
The first chapter is a survey of the types of pollen that honey bees collect at a spatial and temporal scale in developed landscapes. Honey bees showed high floral fidelity for certain pollen types, and there were distinct differences on the types of plants that bees utilized spatially and temporally. In the second chapter, I analyzed the nutritional content of two monofloral pollens and reviewed the strengths and weaknesses of different approaches for nutrient quantification of pollen. Finally, I used the Geometric Framework for Nutrition to model honey bee nutrient regulation. I created artificial diets and manipulated the protein and lipid they contained. After a series of laboratory no-choice and choice assays, I determined that nurse bees prioritized lipid regulation and preferentially consumed diets at a protein-to-lipid (P:L) ratio of 1.5P:1L. Then, in a series of no-choice and choice tests in the field, I presented honey bee colonies with two pollen types that were similar in P:L, but had different amounts of nutritionally relevant fatty acids. Foraging bees put in more foraging effort and displayed high floral fidelity for the pollen with significantly more fatty acids. These results highlight that lipids and fatty acids are more important than what we currently recognize for honey bee nutrition. | en |
