Nutritional Requirements of Bee Species Across Pollen Diets

The study examines interspecific variation in bee nutritional requirements, focusing on how pollen composition—particularly protein, lipids, amino acids, and sterols—affects survival, performance, and mass across bumblebee and honeybee species. Results show that A. mellifera survival is influenced by protein and lipid content, while B. terrestris performance depends on amino acids and sterols. Osmia species exhibit sex-specific responses, with females reliant on protein and males requiring a combination of protein, amino acids, and sterols. The C diet consistently impaired performance across species, especially in B. terrestris and Osmia, due to low amino acid and sterol content. High protein levels did not universally improve outcomes and could be detrimental. Sterols such as β-sitosterol and 24-methylenecholesterol were positively linked to larval growth. The P:L ratio showed no significant effect, but protein thresholds matter. The findings highlight the need for diverse plant resources in agro-ecosystems to support varied bee nutritional needs. Limitations include lack of data on pollen digestibility and secondary metabolites, calling for further research.