Honeybee optomotor behaviour is impaired by chronic exposure to insecticides

Honeybees use wide&[ndash]field visual motion information to calculate the distance they have flown from the hive, and this information is communicated to conspecifics during the waggle dance. Seed treatment insecticides, including neonicotinoids and novel insecticides like sulfoxaflor, display detrimental effects on wild and managed bees, even when present at sublethal quantities. These effects include deficits in flight navigation and homing ability, resulting in decreased survival of exposed worker bees. Neonicotinoid insecticides disrupt visual motion detection in the locust, resulting in impaired escape behaviours, but it had not previously been shown whether seed treatment insecticides disrupt wide&[ndash]field motion detection in the honeybee. Here, we show that sublethal exposure to two commonly used insecticides, imidacloprid (a neonicotinoid) and sulfoxaflor, results in impaired optomotor behaviour in the honeybee. This behavioural effect correlates with altered stress...