Eusociality Shapes Honeybee Breeding: Genetic, Environmental and Temporal Drivers of Colony Phenotypes Favour an Integrated Programme of Population-Based Mass Selection and Landscape-Scale Conservation

This narrative review examines how eusociality reshapes breeding strategies in Apis mellifera and why honeybee colony phenotypes should be interpreted within a population-based framework. Rather than treating colonies as isolated breeding entities, we examine how genetic variation is generated, redistributed, and maintained through reproductive processes, gene flow, and evolutionary forces acting across interconnected populations. The review synthesises evidence on honeybee reproductive genetics, environmental and nutritional influences, management practices, and temporal variation in colony phenotypes. Together, these dimensions motivate a Genotype × Environment × Time (G × E × T) perspective for interpreting colony performance and improving phenotypic evaluation. Existing breeding programmes demonstrate that selective improvement of colony traits is achievable, while highlighting potential trade-offs between genetic gain, inbreeding, and the maintenance of adaptive diversity. Building on this synthesis, we propose a conceptual framework integrating population-based selection and landscape-scale conservation through a gradient of human selection intensity, from protected conservation populations to managed hybridisation zones. This framework aims to reconcile genetic improvement with the preservation of locally adapted diversity and long-term adaptive potential. Its practical feasibility and comparative effectiveness remain to be evaluated empirically.