Within the PoshBee Project we have tested three bee species – honey bees Apis mellifera, bumble
bees Bombus terrestris and solitary bees Osmia bicornis – for their sensitivity to pesticides and
analysed the clearance of pesticides from bees. For each species, all castes and sexes were studied.
We synthesised the mortality data (LD50 or results of limit tests) with the toxicokinetic patterns and
analysed this against the background of inter- and intraspecific variation in life-histories of the tested
bees.
The clearance of sulfoxaflor is relatively similar across all bee species tested and in females after
contact treatment it tends to be retained. The toxicity increases over time independently of the
clearance from the body. The clearance of azoxystrobin was rapid in Osmia and bumble bees, as well
as in honey bee queens, but in honey bee workers there was very little clearance. Similar to sulfoxaflor
the toxicity increased over time, although the residues were detected at very low levels. Glyphosate
tended to be retained in bumble bees after contact treatment but cleared rapidly after oral treatment.
For Osmia bees only in males after contact treatment was the glyphosate almost lost.
The toxicity of a pesticide is dependent on the exact dosage, but also the exposure route and time, as
well as the speed of detoxification and clearance from a body. The assessment for the hazard that a
less toxic pesticide might pose, can be largely dependent on the exposure route. The effects of
pesticide toxicity can increase even after the molecules have been cleared out of the body.Prepared under contract from the European Commission; Grant agreement No. 773921; EU Horizon 2020 Research and Innovation action.Prepared under contract from the European Commission; Grant agreement No. 773921; EU Horizon 2020 Research and Innovation action
