Pollen learning in young honeybees: consumption preferences mediated by experience.

LAJAD, ROCÍO; ANDRÉS ARENAS

Conferencia; Animal Behaviour Live 2021; 2021

Pollen is the main protein resource for honeybees. Its composition differs among plant species, so pollen selection, although poorly understood, affects colony development and productivity. Fresh pollen is not ingested by foragers at the source but transport it to the nest where it is consumed/processed by young/nurse workers. Although colonies avoid collecting some low-quality pollens, foragers themselves would not be able to make foraging decisions based on pollen constituents such as proteins, lipids or some toxic compounds, that being enclosed inside the grain require ingestion to be evaluated. Then, we hypothesized that the adjustment of foragers´ preferences for the most suitable pollens requires the resource to be processed and experienced by young/nurse bees inside the hive. To unveil the mechanisms by which foragers select the most suitable pollens, we performed dual-choice experiments with colonies confined in flying cages (9x3x2m). To confirm that foragers decisions were irrespective of certain pollen constituents, we first measured foragers´ preferences for two monofloral-pollen sources when one of them was offered adulterated with a natural deterrent (amygdalin) and observed that preferences did not differ from the control (with two unadulterated pollens). In turn, we tested foragers´ preferences 2 days after the adulterated pollen had been offered to: i) foragers at the source who introduced the pollen to the nest; ii) all the bees inside the hive; or iii) to young bees that had been transiently isolated from the colony. Differences in pollen preferences among treated and control groups were analyzed by means of linear regression with normal distribution. Interestingly, our results indicate that foragers avoid the pollen that had been experienced as adulterated inside the hive, either if introduced by foragers (i) or by ourselves (ii); however, experienced young/nurse bees alone could not modify responses of inexperienced foragers (iii). Altogether, the results suggest that foraging choices are biased by experiences with pollen of different quality within the nest, although the mechanisms remain unknown.