Manuscript of toxicokinetics of three agrochemicals in three model bee species: Deliverable D3.1

As part of the activities foreseen by the POSHBEE project, we performed experiments to verify the toxicokinetics of three pesticides (the insecticide sulfoxaflor, the fungicide azoxystrobin and the herbicide glyphosate) in the bodies of social bees (Apis mellifera and Bombus terrestris) and solitary bees (Osmia bicornis). For each species all castes and sexes were studied. Based on the results from dose-response assays, sublethal doses were used to treat individuals, which were exposed to the chosen pesticides orally and by contact. Bees were then sampled at multiple time points post- exposure, to capture the breakdown of the active ingredients in the bodies of the organisms. Results of the chemical analyses on bee samples were used for the evaluation of the dynamics of the oral and contact acute exposure in the three species. Overall, the active ingredients sulfoxaflor, azoxystrobin and glyphosate degrade in all species, sex or caste. Nevertheless, there were some exceptions: in honey bee workers, glyphosate administered topically and azoxystrobin administered via the oral route seemed to remain stable in the bees’ bodies even 10 days after exposure (11% and 13% of degradation rate, respectively). We also observed a low degradation of sulfoxaflor following topical exposure in bumble bee queens (26% of degradation rate) and in Osmia bee females (22% of degradation rate). In bumble bees exposed topically to glyphosate degradation was lower than 50% for all sexes and castes. These results deserve further attention by researchers to understand the destiny of these molecules in the bee body and their effects therein.

Prepared under contract from the European Commission; Grant agreement No. 773921; EU Horizon 2020 Research and Innovation action.