Learning of monochromatic stimuli in Apis cerana and Apis mellifera by means of PER conditioning

Abstract

Honey bees are globally distributed and have received increased attention due to their high economic and ecological value for pollination, their exceptional eusocial lifestyle and complex behavioral repertoire. Interestingly, most research on learning and memory in honey bees has been performed in the Western honey bee, Apis mellifera L., and other honey bee species were largely neglected. In the current study, we thus compared visual learning performance of A. mellifera and the Eastern honey bee, A. cerana Fabr., using the proboscis extension response (PER) paradigm. Workers of A. mellifera and A. cerana were differentially conditioned to two monochromatic light stimuli, with peak maxima at 435 and 528 nm. Both honey bee species were able to form an association between the color stimulus and a sugar reward and significantly distinguished between the two color stimuli in a differential discrimination test. However, besides similar performance levels during visual learning, A. cerana showed a reduced mid-term memory (tested after 2 h) compared to A. mellifera. Finally, performance of the visual PER conditioning in our study reached similar levels as found in olfactory PER conditioning, and we thus recommend the visual PER conditioning approach in addition to olfactory conditioning as a useful tool for studying species-specific learning and memory capabilities in honey bees under controlled laboratory conditions.