FORAGING PREFERENCES IN HONEYBEES AFTER EXPERIENCING ADULTERATED POLLEN

ROCÍO LAJAD; ANDRÉS ARENAS

Congreso; Animal Behaviour Live: Annual Online Conference 2021; 2021

ANIMAL BEHAVIOUR LIVE

Pollen is the main protein resource for honeybees but can considerably differ in its composition among plant species, including in the presence of deterrent compounds. It is poorly understood how colonies select the most suitable pollens for optimal development. Fresh pollen is not ingested by foragers at the sources but transported to the nest where it is consumed/processed by young/nurse workers. Although foragers avoid collecting some low-quality pollens, they would not be able to make foraging decisions based on pollen constituents that require ingestion to be evaluated. Then, we hypothesized that the adjustment of foraging preferences for the most suitable pollens requires the resource to be experienced by young/nurse bees inside the hive. To unveil the mechanisms of pollen selection, 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 foraging preferences for two monofloral-pollen sources when one of them was offered adulterated with a deterrent (amygdalin) and observed that preferences did not differ from the control (two unadulterated pollens). We then tested foraging 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) young bees that had been transiently isolated from the colony. Differences in pollen preferences among treated and control groups were analyzed using linear regression with normal distribution. Interestingly, foragers avoid the pollen that had been experienced as adulterated inside the hive, either introduced by foragers (i) or by ourselves (ii); however, experienced young/nurse bees alone could not modify responses of inexperienced foragers (iii). Altogether, our results suggest that foraging choices are biased by experiences with pollen of different quality within the nest, although the mechanisms remain unknown.