Most uses of neonicotinoid pesticides represent a risk to wild bees and honeybees, according to assessments published by the European Food Safety Authority (EFSA).
The Authority has updated its risk assessments of three neonicotinoids – clothianidin, imidacloprid and thiamethoxam – which are currently banned from being used on flowering crops in the EU because of the threat they pose to bees.
For the new assessments, which this time included wild bees (bumblebees and solitary bees), as well as honeybees, EFSA’s Pesticides Unit carried out an extensive data collection exercise, including a systematic literature review, to gather all the scientific evidence published since the previous evaluations.
Jose Tarazona, head of EFSA’s Pesticides Unit, said: “There is variability in the conclusions, due to factors such as the bee species, the intended use of the pesticide and the route of exposure. Some low risks have been identified, but overall the risk to the three types of bees we have assessed is confirmed.”
EFSA finalised its conclusions following two separate consultations with pesticide experts in the EU Member States. The experts have supported the conclusions.
As with the previous assessments, exposure of bees to the substances was assessed via three routes: residues in bee pollen and nectar; dust drift during sowing/application of treated seeds and water consumption.
In response to the updated risk assessment, Dr Philip Donkersley, senior research associate at Lancaster University, said: “All three neonicotinoids evaluated here show high risk for exposing bumblebees through the pollen and nectar that they feed on. This exposure affects solitary bee reproduction, colony viability and learning ability in bumblebees.
“A complete ban on the use of neonicotinoids may not be justified however, as evidence here suggests appropriate use under controlled conditions within greenhouses minimises the risk to all pollinators.”
Global chemical company Bayer disagrees with EFSA’s updated risk assessment conclusions, saying the findings are outside the current mainstream science on bee health, as represented by similar assessments in the US and Canada, which have shown conclusively that neonicotinoid products can be used by farmers to protect their crops without harming honey bee colonies.
EFSA’s conclusions will be shared with risk managers from the European Commission and Member States, who will consider potential amendments to the current restrictions on use of these pesticides.