Enantioselectivity of odor perception in honeybees (Apis mellifera carnica)

The authors tested the ability of 60 free-flying honeybees (Apis mellifera carnica) to discriminate a conditioning odor from an array of 26 simultaneo usly presented substances. The stimuli included 10 pairs of enantiomers and 6 essential oils. The bees (a) significantly distinguished between 98% of the 540 odor pairs tested, thus showing an excellent overall discrimination performance, and (b) were able to discriminate between the optical isomers of limonene, alpha -pinene, beta -citronellol, menthol, and carvone but fa iled to distinguish between the (+)- and (-)- forms of alpha -terpineol, ca mphor, rose oxide, fenchone, and 2-butanol. The findings support the assump tions that enantioselective molecular odor receptors may exist only for som e volatile enantiomers and that insects and mammals may share common princi ples of odor quality perception, irrespective of their completely differing repertoires of olfactory receptors.