Mitochondrial DNA variation in honey bee ( Apis mellifera ) colonies from Arkansas, U.S.

This study characterized the mitochondrial DNA (mtDNA) genetic variation in Arkansas honey bee, Apis mellifera L., by sequencing a portion of the mitochondrial cytochrome oxidase (COI-COII) intergenic region). The samples were primarily of hobbyist-managed origin (n = 180), as well as 32 feral colonies and two swarms. Of the 214 honey bee colonies and swarms sampled, 23 haplotypes were observed. The haplotypes were from the: A (African) (1.87%); C (South eastern European) (92.52%); M (Northern and Western European) (3.27%); and O (Near East and Middle East) lineages (2.34%). Six C lineage haplotypes were predominantly detected (n = 189, 88.31%), all of which are common in U.S. commercial queen breeder colonies. The remaining 27 honey bee samples represented 19 haplotypes, all of which are absent from commercial queen breeder colonies but have been observed in feral honey bee populations collected in other States. These haplotypes, particularly those from the M and O lineages, are likely hundred-year-old remnants of historical importations, surviving for generations despite the arrival of threats, such as Varroa mites. Understanding honey bee genetics and population structure are valuable for maintaining genetic diversity. Results from this study provide evidence that Arkansas honey bee populations differ from U.S. commercial queen breeder colonies. The 15 haplotypes detected in our Arkansas study absent from commercial queen breeder colonies could be important sources of genetic diversity in future honey bee breeding programs, highlighting the importance of State-level genetic surveys.