Presence of a queen (Apis mellifera) reduces the sensitivity of worker bees to environmental risks

Abstract

In honeybees (Apis mellifera), the queen is the central node of the colony; however, the mechanisms through which her presence mitigates the colony’s collective vulnerability to environmental stressors are not well understood. This study investigates the importance of within-colony interactions, particularly the interactions between the queen and worker bees, on colony development under environmental stress. Compared to worker bees in queenless colonies, the presence of a queen resulted in higher survival rates and food intake when exposed to 450 μg/mL of tetracycline. The queen also modulated antioxidant responses, particularly enhancing superoxide dismutase (SOD) activity. Transcriptome analysis indicated that the presence of a queen downregulated the expression of genes involved in the Toll-like receptor (Toll) and Immune deficiency (Imd) pathways, ascorbate and aldarate metabolism, and retinol metabolism in individual worker bees. These results indicate that interactions between queen and worker bees strengthen their immunity and increase the response threshold to environmental stress. Therefore, individual interactions should be included in environmental risk assessments, especially for superorganisms such as honeybees.