Honey bees increase their foraging performance and frequency of pollen trips through experience

Simon Klein,Cristian Pasquaretta,Mathieu Lihoreau,Eirik Søvik,Xu Jiang He,Andrew B Barron,Clint Perry,Jean-Marc Devaud

doi:10.1038/s41598-019-42677-x

Abstract

Honey bee foragers must supply their colony with a balance of pollen and nectar to sustain optimal colony development. Inter-individual behavioural variability among foragers is observed in terms of activity levels and nectar vs. pollen collection, however the causes of such variation are still open questions. Here we explored the relationship between foraging activity and foraging performance in honey bees (Apis mellifera) by using an automated behaviour monitoring system to record mass on departing the hive, trip duration, presence of pollen on the hind legs and mass upon return to the hive, during the lifelong foraging career of individual bees. In our colonies, only a subset of foragers collected pollen, and no bee exclusively foraged for pollen. A minority of very active bees (19% of the foragers) performed 50% of the colony’s total foraging trips, contributing to both pollen and nectar collection. Foraging performance (amount and rate of food collection) depended on bees’ individual experience (amount of foraging trips completed). We argue that this reveals an important vulnerability for these social bees since environmental stressors that alter the activity and reduce the lifespan of foragers may prevent bees ever achieving maximal performance, thereby seriously compromising the effectiveness of the colony foraging force.

Highlights

Social insects are reliant on the forager caste to supply resources for the whole colony[1]
We analysed the foraging activity of 564 bees for which we had information about the type of resource collected for at least one trip (Table 1). These bees performed an average of 19 foraging trips in their lifetime and their foraging span was less than a week
All of them performed a combination of pollen trips and non-pollen trips

Summary

Introduction

Social insects are reliant on the forager caste to supply resources for the whole colony[1]. The authors were not able to measure bees’ foraging performance in terms of amounts or rates of nectar or pollen collection, but only on the number of trips completed. Without this information, it is not possible to know if the most active foragers are the most successful. We analysed how individual bees differed in foraging performance throughout their entire foraging career

Methods

Results

Conclusion