Discriminant conditioning of foragers in the Asian honey bees Apis cerana and A-dorsata

1. Nectivore foraging environments are typically modelled as choices among non-fluctuating rewards, but in reality they often consist of intermittent daily nectar and pollen sources. Intermittent rewards create two distinct foraging problems for colonial nectivores: re-recruitment (periodically returning to intermittent rewards) and re-allocation (finding new rewards). 2. The role of scent in learning and remembering the locations of discontinuous nectar rewards was examined by testing re-recruitment efficiency of Apis cerana and A. dorsata to reward-correlated scents (odour discriminant self-conditioning). Experiments examined the responses of non-naive foragers to an odour correlated with prior reward, and to odours not correlated with prior rewards, by placing different scents into a colony and observing the number of bees re-recruited to a feeding station. 3. Re-recruitment of non-naive foragers in both species was significantly greater in response to the conditioning scent than to the experimental controls. However, species behaviour differed in one aspect; re-recruited A. cerana foragers landed on the feeding station when unscented reward was offered, whereas re-recruited A. dorsata foragers returned but would not land without conditioning scent present in the reward.