Mechanisms mediating pollen selection in Apis mellifera colonies

ROCÍO LAJAD; ANDRÉS ARENAS

Congreso; ANIMAL BEHAVIOUR LIVE: ANNUAL ONLINE CONFERENCE 2023; 2023

ANIMAL BEHAVIOUR LIVE

Many questions about the process by which Apis mellifera colonies evaluate and select pollen remain unanswered. Honey bee foragers can make decisions about pollen selection based on information acquired inside the hive. Recently, we showed that the incorporation of unsuitable pollen within the nest was enough to change foraging preferences. We hypothesize that pollen assessment occurs mediated by young bees after its consumption inside the nest, enabling foragers to learn pollen cues and adjust their preferences to the most suitable pollens. To unveil the mechanisms underlying pollen selection, we explored the transfer of information about pollen suitability through interactions between foragers and in-hive young bees. To this, we performed dual-choice experiments with colonies confined in flying cages (9x3x2m). First, we measured the initial preferences of the foraging population of the colonies for two monofloral pollens, offered in powder at a foraging station inside the cage. For the treatment, we fed bees both pollens as a paste, one of them adulterated with amygdalin, a compound that causes postingestion malaise. The pollens were offered: i) to young bees; ii) to foragers; or iii) to foragers and young bees; all of them transiently isolated from the colony during treatment (48h). For evaluation, we registered the proportion of foragers visiting the monofloral pollens at the station and compared it withtheir initial choices. The interactions with young bees that had experienced amygdalin-adulterated pollen, did not change the preferences of naive foragers (i). When foragers themselves were exposed to adulterated pollen (ii), they did not change their choices either. Finally, we observed that foragers did change their preferences after being exposed to the adulterated pollen in presence of young bees (iii). Taken together, our results suggest that foragers acquire information from pollen-consuming bees while the adulterated pollen is available inside the nest.