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 A III 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 A III 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 Cderived introgression. Iberian honey bee / tRNA leu-cox2 intergenic region / wing geometric morphometrics / DraI test

MtDNA Analysis Indicates Human-Induced Temporal Changes of Serbian Honey Bees Diversity

“…Beekeeping is a dynamic process and according to our field data the traditional way of beekeeping in Serbia gradually disappeared over the past decade, which may be one of the reasons for observed changes in genetic variability. Human-induced temporal changes in honey bee subspecies and genetic diversity were previously reported and recognized [ 24 , 64 , 65 , 66 ]. Many of these changes were explained by the intentional introduction of bee subspecies preferred by beekeepers [ 15 ] and sometimes these introductions have unintentional consequences [ 24 ].…”

Can introgression in M-lineage honey bees be detected by abdominal colour patterns?

“…In accordance with those surveys, all phenotypes collected in Iberia were revealed to be pure. Introgressed A. m. iberiensis individuals (0.055 ≤ Q-values ≤ 0.210) were all from the Azores, where a high frequency of C-lineage haplotypes still exists in several islands (De la Rúa et al 2006;Ferreira et al 2019;Muñoz et al 2013). The ancestors of the extant C-derived colonies were mostly introduced in the 1980s in the framework of a breeding program using A. m. ligustica (Ferreira et al 2019).…”

“…Owing to recurrent introductions of C-lineage queens over the last decades, honey bee's natural range has been changing dramatically in Europe, especially in the territories of A. m. mellifera in northern Europe and of A. m. iberiensis in the Canaries and Azores (De la Rúa et al 2006;De la Rúa et al 2001;De la Rúa et al 2002;Ferreira et al 2019;Jensen et al 2005;Muñoz et al 2013;Muñoz et al 2014;Pinto et al 2014;Soland-Reckeweg et al 2009). To counteract the demise of the dark bee in northern Europe and of the Canarian black bee in some Canary Islands, conservation efforts have been implemented to protect these subspecies or local variants/ecotypes from further decline (De la Rúa et al 2009; Muñoz and De la Rúa 2012).…”

“…Irish beekeepers often re-queen colonies that contain variable yellow-banding phenotypes in order to protect and conserve the dark bee. In contrast, in the Azores, many beekeepers prefer and select for the yellow-banding phenotypes that were originally introduced with C-lineage queens in the 1980s (Ferreira et al 2019). However, colour-based selection may negatively impact population diversity and is futile if there is no real association between the abdominal colour and the genetic background of the honey bees in a particular colony.…”

Historical Changes in Honey Bee Wing Venation in Romania

“…Studies based on whole-genome sequencing [32,33] detected clear temporal differences. In the Azores, where honey bees were probably introduced by colonisers [34], changes in mitotype composition varied between individual islands [35]. In some of these, there were marked increases in bee populations from Lineage C [35].…”