Historical and contemporaneous human-mediated processes left a strong genetic signature on honey bee populations from the Macaronesian archipelago of the Azores

Abstract

In this study, honey bees from the Macaronesian archipelago of the Azores were extensively surveyed to unveil diversity patterns. A total of 638 colonies were analyzed over two time periods using mtDNA and wing geometric morphometrics. The genetic composition revealed to be heterogeneous and related to historical and contemporary human-mediated introductions. The close relationship of Azorean populations with those from northern Portugal supports historical introductions by Portuguese settlers. The African sublineage AIII prevailed on five islands, contrasting with three islands where C haplotypes were dominant. On Pico and Graciosa, C haplotypes are due to recent imports of commercial queens. On Faial, the sudden replacement of AIII by C haplotypes coincided with arrival of Varroa destructor. This study deepens the current understanding of Macaronesian honey bees, suggesting that they are variants of the Iberian honey bee with differential levels of C-derived introgression.