Marked interspecific differences in the neuroanatomy of the male olfactory system of honey bees (genus Apis)

Using neuropile staining and confocal microscopy, the authors analyze the morphology of the male antennal lobe in 5 honey bee (Apis) species, showing remarkable differences in these species' equipment in hypertrophied morphological units, the macroglomeruli. They propose a putative scenario of antennal lobe evolution in Apis. AbstractAll honey bee species (genusApis) display a striking mating behavior with the formation of male (drone) congregations, in which virgin queens mate with many drones. Bees' mating behavior relies on olfactory communication involving queen —but also drone pheromones. To explore the evolution of olfactory communication inApis, we analyzed the neuroanatomical organization of the antennal lobe (primary olfactory center) in the drones of five species from the three main lineages (open ‐air nesting species: dwarf honey beesApis florea and giant honey beesApis dorsata; cavity ‐nesting species:Apis mellifera, Apis kochevnikovi, andApis cerana) and from three populations ofA. cerana (Borneo, Thailand, and Japan). In addition to differences in the overall number of morphological units, the glomeruli, our data reveal marked differences in the number and position of macroglomeruli, enlarged units putatively dedicated to sex pheromone processing. Dwarf and giant honey bee species possess two macroglomeruli while cavity ‐nesting bees present three or four macroglomeruli, suggesting an increase in the complexity of sex communication during evolution in th...
Source: The Journal of Comparative Neurology - Category: Neurology Authors: Tags: RESEARCH ARTICLE Source Type: research