Avoidance response to low-quality pollen in foraging honeybees.

LAJAD, ROCÍO; ARENAS A

Encuentro; 36th Annual meeting of the International Society of Chemical Ecology 2021; 2021

Deterrent substances present in food, like toxic and/or bitter compounds, can exert repelling responses. Pollen, the main protein resource for Apis mellifera, may present compounds that induce distasteful and/or malaise experiences. Although honeybee colonies avoid collecting some low-quality pollens, evidence supports that foragers themselves are not able to make foraging decisions based on pollen composition at the food sources. We hypothesize that assessment occurs after pollen is processed inside the nest, likely mediated by young bees. To unveil the mechanisms that enable foragers to avoid low-quality pollens, we performed dual-choice experiments with flying bees confined in cages (9x3x2m). We compared foragers´ preferences for two monofloral-pollen sources before and after one of them was adulterated with amygdalin. The adulterated pollen was offered either: i) to all the bees inside the hive; ii) to foragers at the pollen source or iii) to young bees transiently isolated from the colony during the treatment. Controls with unadulterated pollens were included. Foragers significantly reduced their preferences for pollens that had been experienced as adulterated inside the hive (i). Interestingly, they could not avoid the adulterated pollen experienced directly at the food source (ii), but they did after the pollen was incorporated into the nest. Experienced young bees could not modify responses of inexperienced foragers (iii). Altogether, results suggest that pollen assessment requires the resource to be processed in the colony and rule out that experienced young bees alone could bias foraging preferences.