The European Food Safety Authority (EFSA; Parma, Italy) has confirmed that “most uses of neonicotinoid pesticides represent a risk to wild bees and honeybees.” The conclusion was based on an updated risk assessment of three neonicotinoids that are currently subject to usage restrictions in the European Union because of the threat they pose to bees. These new conclusions update those published in 2013, after which the European Commission imposed controls on use of the substances, clothianidin, imidacloprid, and thiamethoxam.
EFSA’s pesticides unit carried out an extensive data collection exercise for the new assessment, including a systematic literature review, to gather all the scientific evidence that has been published since the previous evaluation. The latest assessment also covers wild bees—bumblebees and solitary bees—as well as honeybees.
EFSA finalized its conclusions following two consultations with pesticide experts in the EU member states. The experts have supported the EFSA 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 the sowing/application of the treated seeds; and water consumption.

“The availability of such a substantial amount of data as well as the guidance has enabled us to produce very detailed conclusions,” says Jose Tarazona, head of EFSA’s pesticides unit. “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,” Tarazona says.
EFSA’s conclusions will now be shared with risk managers from the European Commission and EU member states, who will consider potential amendments to the current restrictions on the use of these pesticides.
Bayer says that it fundamentally disagrees with EFSA’s conclusions for imidacloprid and clothianidin. The company says that EFSA’s findings place it outside the current mainstream science on bee health, as represented by recent similar assessments carried out by agencies such as the US EPA and Canada’s Pest Management Regulatory Agency (PMRA). Those assessments have shown conclusively that neonicotinoid products can be used by farmers to protect their crops without harming honeybee colonies, according to Bayer.
The company says that EFSA’s risk assessments are based on a bee guidance document, which it says disregards the interests of EU member states, and that EFSA’s conclusions cannot be used as a measure to justify further restrictions in the use of neonicotinoids. Although challenges to bee health remain owing to of a number of factors, the total number of beehives in the European Union is continuing to rise, according to Bayer.