With or without foraging for food, field-realistic concentrations of sulfoxaflor are equally toxic to bumblebees (Bombus terrestris)

摘要

Over the past decades, the effects of pesticides on bee health have gained a lot of attention due to the value of bees as pollinators. Sulfoxaflor is a recently developed systemic insecticide in the new sulfoximine class of insecticides and has shown high efficiency against a wide range of pest insects. The main objective of this study was therefore to assess the effects of sulfoxaflor on the buff-tailed or large earth bumblebee (Bombus terrestris), known as an important generalist pollinator of wild plants and many agricultural crops worldwide. To achieve this objective, a laboratory bioassay with queenless bumblebee microcolonies that had been previously developed and used to assess for both toxicity and effects on foraging behaviour in B. terrestris for neonicotinoid insecticides (imidacloprid and thiamethoxam), was specifically employed. Here, microcolonies of B. terrestris workers, with or without the need to forage for food, were exposed to sugar water supplemented with field-realistic concentrations of sulfoxaflor (starting from 15 mu g/ml to 5 and 1 mu g/ml) via oral exposure during 15 days. In addition to a significant reduction in bumblebee worker survival, the results also indicated that there was no higher toxicity caused by sulfoxaflor when the bumblebees had to forage for their food compared to when they did not have to forage. These results could guide future studies in this context and could be used in debates on insecticides and/or risk assessment of pesticides with potential effects on behaviour in bumblebees and other pollinators in general.