Bee Health Definition and Key Indicators for Honeybees and Bumblebees

Bee health is defined through a hierarchical framework of interdependent biological systems, including molecular, microbial, parasitic, nutritional, social-behavioural, environmental, and population-genetic dimensions. This comprehensive approach integrates the One-Health concept, emphasizing the link between bee health and environmental well-being. The document establishes key health indicators across species, focusing on honeybees and bumblebees, with metrics for immune response, microbiome composition, Varroa destructor infestation, pollen quality, and genetic diversity. It highlights the impact of pesticides like neonicotinoids and clothianidin on immune function and reproduction, as well as the role of landscape heterogeneity and nutrition in resilience. Molecular indicators such as vitellogenin and antimicrobial peptides, behavioural tests like the Proboscis Extension Reflex, and ecological factors such as nesting site availability are emphasized. The report supports holistic, context-sensitive monitoring using measurable, replicable, and relevant indicators to guide conservation and management strategies in the face of climate change and anthropogenic stressors.