Honeybee lifespan: the critical role of pre-foraging stage

Abstract

Assessing the various anthropogenic pressures imposed on honeybees requires characterizing the patterns and drivers of natural mortality. Using automated lifelong individual monitoring devices, we monitored worker bees in different geographical, seasonal and colony contexts creating a broad range of hive conditions. We measured their life-history traits and notably assessed whether lifespan is influenced by pre-foraging flight experience. Our results show that the age at the first flight and onset of foraging are critical factors that determine, to a large extent, lifespan. Most importantly, our results indicate that a large proportion (40%) of the bees die during pre-foraging stage, and for those surviving, the elapsed time and flight experience between the first flight and the onset of foraging is of paramount importance to maximize the number of days spent foraging. Once in the foraging stage, individuals experience a constant mortality risk of 9% and 36% per hour of foraging and per foraging day, respectively. In conclusion, the pre-foraging stage during which bees perform orientation flights is a critical driver of bee lifespan. We believe these data on the natural mortality risks in honeybee workers will help assess the impact of anthropogenic pressures on bees.

Delayed effects of a single dose of a neurotoxic pesticide (sulfoxaflor) on honeybee foraging activity

“…They were then released into a colony equipped with a bee counter, which consists of a camera that monitors the hive entrance and image analysis software that detects and registers the activity of bees (direction: in or out of the hive, and time of activity: day, hour, minute, and second) (Prado et al 2020). The experiment was repeated five times in 2019 (2 in May, 2 in June and 1 in July) using three different colonies equipped with bee counters (2 colonies were used twice).…”

“…In honeybees, foraging activity is preceded by orientation flights, during which individuals develop highly complex cognitive capacities essential to navigation and homing (Capaldi and Dyer 1999;Degen et al 2016). The experience accumulated during this pre-foraging stage then positively influences their foraging capacities and lifespan (Prado et al 2020). We therefore hypothesized that a perturbation of this neurocognitive process by a neurotoxin could trigger chronic effects.…”

“…We therefore hypothesized that a perturbation of this neurocognitive process by a neurotoxin could trigger chronic effects. To test this hypothesis we exposed bees at 7-days old, the median age of first orientation flights (Requier et al 2020;Prado et al 2020), to two sublethal doses of sulfoxaflor and tracked their flight activity and lifespan with automated life-long monitoring devices (optic bee counters) (Prado et al 2019(Prado et al , 2020.…”

Where Is the Honey Bee Queen Flying? The Original Case of a Foraging Queen

“…From a biological point of view, it is important to highlight that the worker honey bees need to train themselves by participating in pre-foraging flights before becoming foragers [6] and, similarly, queens perform orientation flights before participating in mating flights [7,8].…”

“…The pre-foraging stage for workers, as the pre-mating stage for the queens, represents a critical phase which includes high mortality risks due to environmental hazards (e.g., pollution, parasites, climate and predation) [6,9]. However, this stage is fundamental because it allows bees to acquire cognitive capacities essential for their future performance, such as navigation and homing [8,10,11].…”