Defining bee races
The different bee races are determined using biometric traits (coloration, indices, etc.) as well as molecular markers (mitochondrial and nuclear). Defining races allows us to understand the biogeography of the honey bee.
There is a center of dispersal located north of the Persian Gulf from which honey bees colonized Europe. Pleistocene glaciations led to the isolation of populations and to the formation of distinct races. After the retreat of the ice, the different races interbred again: the conservation and breeding of pure races therefore currently runs counter to natural processes.
However, conserving pure races makes it possible to benefit from the heterosis effect (heterozygous individuals) through simple crossbreeding. Breeding in pure lines does not necessarily result in better conservation of genetic biodiversity compared to crossbreeding, as crosses represent rearrangements of pre-existing genes.
Pure-breed selection promotes biodiversity if it allows the preservation of certain alleles in a given context (e.g. swarming tendency, aggressiveness, frame adherence). In this case, the objective is to create a “bank of rare alleles” that may prove necessary in the future.
Defining honey bee races – methods, genetics and biogeography
All domesticated honey bees used in beekeeping belong to the species Apis mellifera. Within this species, considerable diversity exists and is traditionally described in terms of races or subspecies. The document emphasizes that the concept of “race” is not strictly defined biologically and is used pragmatically to describe groups sharing common traits and a relatively recent evolutionary history. Races must be distinguished from ecotypes, which reflect local adaptation, and from populations defined solely by geography.
Three complementary approaches are used to differentiate honey bee races. The first is morphometric analysis, which quantifies traits such as abdominal coloration, hair length, tomentum width, tongue length, cubital index and discoidal shift of the forewing. Statistical analyses allow discrimination among several races, although hybridization can blur boundaries.
The second approach is ethology. Behavioral differences among races have been described, including gentleness, swarming tendency, orientation ability, propolis use and comb construction. These traits are highly relevant for beekeeping practice but are strongly influenced by selection and environmental conditions.
The third approach is molecular genetics. Analysis of mitochondrial DNA, inherited exclusively from the queen, allows assignment to major evolutionary lineages using COI–COII intergenic regions. Analysis of the nuclear genome using microsatellite markers provides a more comprehensive picture by including paternal contributions and revealing introgression and hybridization.
Integrating these data leads to the recognition of four major evolutionary lineages of Apis mellifera: lineage M (western Europe), lineage C (central and southeastern Europe), lineage A (Africa) and lineage O (Caucasus and Near East). Biogeographically, a Near Eastern origin is proposed, followed by diversification during the Pleistocene glaciations and extensive mixing after glacial retreat and through human-mediated movements.
All races are interfertile, and modern populations are often highly hybridized, particularly due to queen importations. Maintaining so-called pure races is therefore not a natural state, but it may be useful as a conservation strategy to preserve rare alleles and to exploit heterosis effects through controlled crossing.
In conclusion, defining honey bee races requires an integrated framework combining morphology, behavior and genetics. Honey bee races are dynamic evolutionary entities, and their management must balance local adaptation, genetic diversity and beekeeping objectives.
See also:
- Apis mellifera & other Apis
- Introduction to bee genetics
- The bee genome
- Does selection in beekeeping allow heritability?
- Queen rearing in the Carnica population: genetics, selection and practice