Since December 2013 the use of imidacloprid, clothianidin and thiamethoxam seed treatments has been prohibited on flowering crops and spring sown cereals in the EU.
At the end of March 2017, the Commission put forward a proposal to restrict all outdoor uses of clothianidin, imidacloprid and thiamethoxam, including seed treatments. The only use permitted would be in permanent greenhouses where the crop stays its entire life cycle within the greenhouse.
Last week Michael Gove indicated that the UK supports these further restrictions, and unless the scientific evidence changes, the UK government will maintain these additional restrictions post-Brexit.
The UK's position on the three neonicotinoids was made following a request from Defra to the Expert Committee on Pesticides (ECP) for advice on the risks to pollinators posed by the three neonicotinoids.
The ECP's role is to provide independent, impartial advice to the government on the science relating to pesticides. The ECP reviews scientific reports on a regular basis and advises Ministers on these findings.
In July 2017 the ECP reviewed 34 reports including studies by Woodcock et al and Tsetkov et al, and published ‘Advice to Departments’ in October 2017.
Although some of the observations from the studies reviewed are outside regulatory endpoints, the ECP considered that they add to the range of plausible mechanisms which may explain some of the observed effects of the three neonicotinoids on bees in laboratory and field studies.
The ECP concluded that;
- Exposure to the three neonicotinoids under field conditions can have an unacceptable effect on bee health. These effects occur at a landscape level and between seasons.
- The three neonicotinoids are relatively persistent in the environment and can occur in non-target plants foraged by bees.
- Bumblebees and solitary bees are negatively affected by exposure to neonicotinoid residues from across the landscape.
- The unacceptable effects of the three neonicotinoids are not always apparent and are driven by environmental factors such as availability of food for bees and bee health.
- Precise risk management is difficult at the current levels of uncertainty and this presents a major challenge to risk management.
Based on these conclusions the ECP stated that when recent studies are considered collectively, it is difficult to provide certainty that there is an acceptable risk to pollinators from the use of the three neonicotinoids on flowering crops, and so the ECP supports the current restrictions on flowering crops and spring cereals.
In addition, the new evidence on neonicotinoid residues in plants in non-cropped areas has raised ECPs concerns about the use of the three neonicotinoids on non-flowering crops.
Despite the lack of published peer-reviewed studies providing evidence of environmental persistence and a direct impact on pollinators the ECP considers that impacts could occur if;
- residues of neonicotinoid seed treatment on non-flowering crops persisted in the soil to be taken up by flowering crops in subsequent years and;
- neonicotinoid seed treatments on non-flowering crops contaminated non-cropped areas leading to uptake by, for example, wildflowers in hedgerows.
The ECP identified a number of data gaps and areas for further study to better understand these risks.
Therefore based on the limited number of studies to date the ECP considers that the further restrictions on the three neonicotinoids, proposed by the Commission in March 2017, could be justified.