Biomarkers of nutritional and health status in Apis mellifera

Wild and managed bees are increasingly threatened by environmental pollution, climate change, and pathogens, which together pose risks to their survival and the ecosystems. Traditional methods of assessing colony health provide general insights but are subjective and lack detailed information, while a rapid and practical method for routine application is still unavailable. Therefore, the primary aim of this research project was to identify a panel of biomarkers in honey bee hemolymph capable of assessing nutritional and health status at the colony level, and to test these biomarkers under different field conditions. Recognizing the critical role of nutrition in honey bee health, the relationship between the identified biomarkers and nutritional supplementation was also investigated. Finally, the study evaluated the influence of season and farm management on the content of essential and potentially toxic trace elements in honey bees from different Italian regions. The research identified and tested under field conditions a panel of hemolymph biomarkers including apolipophorin I, vitellogenin, apolipophorin II, transferrin, hexamerin 70a, and total protein concentrations. Honey bees fed with different pollen types didn’t report significant variations in hemolymph protein concentrations, while the supplementation of a by-product of phycocyanin extraction from Spirulina (Arthrospira platensis), did not apport adverse effects or significant differences from control bees observed. Regarding the use of honey bees as bioindicators, it was recognized that conventional apiaries had a higher risk of exposure to copper than organic apiaries, leading to a possible dysregulation of iron homeostasis. In conclusion, this research presents a novel panel of biomarkers for colony health assessment that fills gaps in current methodologies and highlights the importance of an interdisciplinary approach to address the challenges facing beekeeping. These findings contribute to the advancement of honey bee monitoring and underline the interrelationship between environmental, animal, and human health.