The impact of neonicotinoids on honey bees

(PhD Project)

The use of the harmonic radar technology allowed us to see the homing trajectories of control and treated bees exposed chronically to sublethal doses of neonicotinoids in the field and thus understand better the reason of honey bees' homing failure reported in previous studies (Henry et al. 2012; Fischer et al. 2014). The use of counters at the feeder's entrances and electric field recordings (Greggers et al 2013) in the hives allowed us to investigate the effects of neonicotinoids on foraging behavior in field conditions. In a first study, we revealed negative effects of the chronic and sub-lethal exposure to thiaclorpid on foraging behavior, navigation and recruitment behavior via dance communication (Tison et al. 2016) Comparable effects were found on the foraging behavior of honey bees for another substance, clothianidin (article in prep.)

Another part of this project was to investigate the effects of thiacloprid and clothianidin on honey bees' sucrose responsiveness, learning and memory abilities. With laboratory and semi-field experimentens we investigated whether the sucrose responsiveness of bees exposed to sublethal doses of thiacloprid, Calypso® (a thiacloprid-based formulation) or clothianidin was impaired. Using the PER conditioning paradigm we studied the effetcs of thiacloprid, the formulation Calypso® and clothianidin on the learning and memory performances of honey bees. By acutely intoxicating bees with different sublethal doses at different timings we studied the effects of these substances on the acquisition function and on the different phases of the memory.