Changes with age in olfactory conditioning performance of worker honey bees (Apis mellifera)

Proboscis extension reflex conditioning has often been used to study olfactory learning in the honey bee. However, only a few studies have explored the variability of this response relative to the age of the bees, and these studies have yielded different conclusions. We aimed to document the effect of age on the proboscis extension response by measuring three parameters in the experimental procedure: the level of spontaneous responses, the acquisition rate, and the resistance to extinction. The performance of the youngest bees (2-day and 4-day-old) differed from those of older individuals for the three parameters, which may be related to the ontogeny of the olfactory system. In older age-groups, only the resistance to extinction was found to vary with age. We discuss the possible relationships between age-dependent variations in the odour learning abilities and the division of labour in the colony