Modulation of pesticide response in honeybees

Honeybee exposure to pesticides is widely accepted, but the role they play in impacting bee health remains controversial. The development of risk assessment procedures is notably a difficult task due to the variability of responses observed for a single pesticide at a specific dose. Indeed, honeybees, during most of their lifetime, are exposed to fluctuating environmental conditions (e.g., pathogen pressure, resource availability, climatic conditions) and can go through important physiological changes within a few days (e.g., behavioral maturation) or even a day (e.g., circadian clock), which are all factors that can affect the bee response to pesticides. Integrating the range of variability in conditions experienced by bees is relevant to honeybee toxicology and will contribute to a better assessment of their susceptibility to pesticides. The aim of this review is therefore to provide empirical evidence of how co-exposure to stressors, and environmental and endogenous factors modulate the honeybee response to pesticide.