Abstract

Several species of social bees exhibit population-level lateralization in learning odors and
recalling olfactory memories. Honeybees Apis mellifera and Australian social stingless bees Trigona
carbonaria and Austroplebeia australis are better able to recall short- and long-term memory through
the right and left antenna respectively, whereas non-social mason bees Osmia rufa are not lateralized
in this way. In honeybees, this asymmetry may be partially explained by a morphological
asymmetry at the peripheral level—the right antenna has 5% more olfactory sensilla than the left
antenna. Here we looked at the possible correlation between the number of the antennal sensilla
and the behavioral asymmetry in the recall of olfactory memories in A. australis and O. rufa. We
found no population-level asymmetry in the antennal sensilla distribution in either species
examined. This suggests that the behavioral asymmetry present in the stingless bees A. australis may
not depend on lateral differences in antennal receptor numbers.