Stress decreases pollen foraging performance in honeybees

Abstract

Foraging in honeybees is energetically demanding. Here, we examined whether stressors, which generally increase metabolic demands, can impair foraging performance. A controlled non-pathogenic stressor (immune challenge) resulted in a change in the foraging preferences of bees. It reduced pollen foraging and increased the duration of trips in pollen foragers. Stress also reduced the amount of octopamine in the brain of pollen foragers (a biogenic amine involved in the regulation of foraging and flight behaviour in insects). According to the literature, flight metabolic rate is higher during pollen foraging than during nectar foraging, and nectar gives a higher energetic return relative to the foraging effort when compared with pollen. We thus propose that stress might be particularly detrimental to the performance of pollen foragers, and stressed bees prefer the energy-rich resource of nectar. In conclusion, stress, even at low levels, could have consequences for bee foraging behaviour and thereby the nutritional balance of the colony.

Evaluating the Impact of Post-Emergence Weed Control in Honeybee Colonies Located in Different Agricultural Surroundings

“…In addition, Kendall's rank test shows a positive and significant correlation between pollen foragers' incoming rate and hive bees' relative expression of CYP6AS4. Consistently, previous studies indicate that pollen foraging is reduced by stress and exposure to pesticide mixtures [10,11] and that pollen intake affects the level of CYP450 transcripts [75,76]. Indeed, one of the two principal characteristics of agricultural intensification across all global landscapes, besides the increased reliance upon pesticides, is the reduction of floral diversity, resulting in a shift from heterogeneous habitats to more homogeneous ones [77].…”

“…In this sense, honeybees depend on the adequate availability and collection of pollen to meet most of their dietary needs. Stress and exposure to pesticide mixtures decrease pollen foraging performance in honeybees [10,11], leading to a nutritional imbalance with a pollen deficit at the colony level, and thereby affects colony development [10]. Hence, pollen balance is central to the growth and sustainability of colonies affecting many downstream processes such as brood rearing and behavioral development of workers, and also interactions between diet, nutrition and disease and/or immune system status [12].…”

Microfluidics of binary liquid mixtures with temperature-dependent miscibility

“…The use of binary liquid mixtures with temperaturedependent miscibility is in our view a promising approach for temperature-controlled microfluidics, in particular in applications involving multi-stage processes and mass transfer across interfaces. Applications of such molecular systems may be multi-fold and include drug delivery, 57 catalysis, 58 extraction and separation of bioactive compounds, 59 micelle-mediated pre-concentration protocols 60,61 and alternating current cloud point extraction. 62…”

Automated monitoring of bee behaviour using connected hives: Towards a computational apidology

“…Using motion detection cameras and RFID sensors at the hive entrance, it is possible to identify the type of food (nectar/water or pollen) collected by each forager and how this varies through time. This approach revealed a combined specialisation of bumblebee foragers for nectar and pollen (Russell et al 2017) as well as the impact of different types of environmental stressors on pollen collection by honey bee foragers (Bordier et al 2018).…”