Aversive Conditioning in Honeybees (Apis melliferd)

Learning in honeybees, previously studied by appetitive techniques, was studied here by aversive techniques. In one series of experiments, a shuttle box was used, with the odor of formic acid as the aversive stimulus. A punishment contingency was found to suppress shuttling more in master animals than in yoked controls, whereas escape and unsignaled avoidance contingencies facilitated shuttling in master animals compared with yoked controls. In a second series of experiments, the subjects were unrestrained foragers flying back and forth between the hive and the sill of an open laboratory window to take sucrose solution from targets so constructed that shock could be delivered while the proboscis was in contact with the solution. A group of animals trained to discriminate between two differently colored targets, one providing sucrose and the other sucrose plus immediate shock, performed as well as a group trained with sucrose and tap water, and better than a group trained with sucrose and sucrose plus delayed shock. Animals for which a signal was paired with shock while they were feeding from a single target quickly learned to avoid the shock by flying off the target. The effectiveness of the pairing was demonstrated both by an explicitly unpaired procedure (which retarded acquistion when the signal and shock subsequently were paired) and by differential conditioning. This work substantially extends the range of vertebrate learning phenomena found in honeybees.