Mitochondrial genome diversity within Apis mellifera subspecies

Apis mellifera Linnaeus 1758 (western honey bee) has about 30 recognized subspecies spread throughout Africa, the Middle East, Europe and western Asia. Introduced populations of honey bees can be found globally. In the USA, managed honey bee breeds originate from the introduction of five European subspecies prior to 1922. Despite importation restrictions, Africanized honey bees (AHB) have become widespread throughout the southern states, after successfully invading north from Brazil. This widespread native distribution, broad introduced range, and invasive spread of A. mellifera offer an opportunity to explore adaptations to a range of environmental conditions. However, in order to leverage this natural experiment fully, we need rapid, accurate A. mellifera subspecies identification methods. Current methods are sufficient to identify honey bees to morphometric or molecular clades, often referred to as lineages. Within these clades, the identification of specific subspecies, breeds, or strains, including AHB, can be challenging. We aim to improve understanding of the mitochondrial clades using broader representation of North African, and African/Near East honey bees. With a total of 91 mitochondrial genomes, both from morphometrically confirmed honey bees obtained from the Ruttner Bee Collection at the Bee Research Institute in Oberursel, Germany, and existing data from GenBank, we investigated: 1) how many major mitochondrial clades exist and 2) for subspecies with broad geographic ranges, if there is a strong biogeographic signal in the mitogenome. This information will be used to identify which mitochondrial genes could be targeted to develop more specific subspecies marker(s) for future work on phenotypic plasticity.