VIEWPOINT

BROAD BRUSH CONDEMNS NEONICS

Rothamsted Research comments on a European evaluation of the unintended risks to bees from neonicotinoid pesticides that again highlights the need for more detailed studies.

  • 02
  • MAR
  • 2018

The European Food Safety Authority has published its evaluation of research that assesses the risks to wild bees, honeybees and solitary bees of the three neonicotinoids that have been the subject of EU restrictions on their use since 2013.

EFSA's Pesticides Unit began the review in 2015: “Evaluation of the data on clothianidin, imidacloprid and thiamethoxam for the updated risk assessment to bees for seed treatments and granules in the EU” was published on Wednesday, 28 February.

Its technical report, which details methodologies, and the accompanying peer reviews of research on each of the three pesticides amount to 341 pages of documentation. The conclusions update those of 2013, which led to the European Commission’s restrictions.

“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,” says Jose Tarazona, Head of EFSA’s Pesticides Unit. “Some low risks have been identified, but overall the risk to the three types of bees we have assessed is confirmed.”

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.

EFSA’s latest conclusions will now be shared with risk managers from the European Commission and Member States, who will consider potential amendments to the current restrictions on the use of these pesticides.

Comment from Rothamsted Research

Lin Field, Head of the Department of Biointeractions and Crop Protection
“The EFSA reports are very dense and hard to read and the summaries not always helpful. I have brought the conclusions together (see below), and have added my comments (in red italics).

“Overall, for exposure from the most likely routes, nectar and pollen, the higher tier assessments, where they could be performed, show either that the available data ‘did not allow a low risk to be demonstrated, despite not indicating a clear high risk’ (clothianidin and thiamethoxam) or ‘low risk for some crops for honeybees’ (imidacloprid). This is hard to interpret.

“Taken together, the reports seem to suggest that use of these pesticides should really be assessed on a compound-by-compound and a crop-by-crop basis, but this is probably impractical. Also, the criteria used, if applied to other pesticides, would probably suggest a ban for all of them.

“The potential problems of using any pesticide have to be balanced against the need to protect crops from pests. The three neonics studied here might be useful in some situations and, more importantly, there are other neonicotinoids that are much less toxic to bees; it would be a shame if these were tarred with the same brush.”

For exposure via…

clothianidin

imidacloprid

thiamethoxam

residues in pollen and nectar:

• low risk for some bee groups/use/scenario combinations;

• high risk in other cases;

• where a higher tier (Tier 3) risk assessment could be performed, the available data did not allow a low risk to be demonstrated, despite not indicating a clear high risk.

• where a higher tier (Tier 3) risk assessment could be performed, low risk for some crops for honeybees;

• when all the bee groups (honeybees, bumblebees and solitary bees) are considered, a high risk was concluded;

• or it was concluded that a low risk was not demonstrated for all the uses assessed.

• low risk for some bee groups/use/scenario combinations;

• while a high risk in other cases;

• in the majority of cases where a higher tier (Tier 3) risk assessment could be performed, the available data did not allow a low risk to be demonstrated, despite not indicating a clear high risk.

Most likely source of exposure – suggests some bee groups/use/scenario combinations are OK, others not.”

Most likely source of exposure – suggests some bee groups/use/scenario combinations are OK, others not.

Most likely source of exposure – suggests some bee groups/use/scenario combinations are OK, others not.

residues from dust drift during the sowing/application of the treated seeds:

• low risk to honeybees for the use to sugar and fodder beat (sic);

• for bumblebees and solitary bees, a low risk was not demonstrated with a screening assessment;

*for all other outdoor uses, high risk to honeybees and bumblebees;

• for solitary bees, a low risk was not demonstrated with a screening assessment.

• low risk for some crops for honeybees;

• when all the bee groups (honeybees, bumblebees and solitary bees) are considered, a high risk was concluded;

• or it was concluded that a low risk was not demonstrated for all the uses assessed.

• low risk for those uses that foresee planting in permanent greenhouses;

• for all other uses, either a high risk or the assessment could not be finalised.

Less likely source of exposure (if sowing/application done correctly) – suggests use in beet may be OK.

Less likely source of exposure (if sowing/application done correctly) – suggests use in some crops OK.

Less likely source of exposure (if sowing/application done correctly) – suggests use in some crops OK.

water consumption:

• low risk to honeybees for all uses via residues in puddles;

• low risk to honeybees for residues in guttation fluid for the uses to winter cereals, sugar beet and potatoes;

• high risk for all other uses;

• risk assessment for honeybees from exposure via surface water could not be performed;

• low risk to honeybees, bumblebees and solitary bees for the use to maize and sweet maize which will be sown and maintained in permanent greenhouses;

• risk assessment for the granular use to forestry nursery could not be performed with the available information.

• low risk to honeybees for all uses via residues in puddles or via surface water;

• low risk to honeybees for residues in guttation fluid for the uses to winter cereals, sugar beet and potatoes;

• high risk for all other uses.

• low risk to honeybees for all uses via residues in puddles;

• low risk to honeybees for residues in guttation fluid for the uses to sugar beet;

• high risk for all other uses;

• a risk assessment for honeybees from exposure via surface water could not be performed.

Less likely source of exposure – suggests generally low risk in winter cereals, sugar beet and potatoes, and maize in greenhouses.”

Less likely source of exposure – suggests generally low risk for cereals, sugar beet and potatoes.

Less likely source of exposure – suggests generally low risk for sugar beet.

About Rothamsted Research
Rothamsted Research is the longest-running agricultural research institute in the world. We work from gene to field with a proud history of ground-breaking discoveries, from crop treatment to crop protection, from statistical interpretation to soils management. Our founders, in 1843, were the pioneers of modern agriculture, and we are known for our imaginative science and our collaborative influence on fresh thinking and farming practices.
Through independent science and innovation, we make significant contributions to improving agri-food systems in the UK and internationally. In terms of the institute’s economic contribution, the cumulative impact of our work in the UK was calculated to exceed £3000 million a year in 20151. Our strength lies in our systems approach, which combines science and strategic research, interdisciplinary teams and partnerships.
Rothamsted is also home to three unique resources. These National Capabilities are open to researchers from all over the world: The Long-Term Experiments, Rothamsted Insect Survey and the North Wyke Farm Platform.
We are strategically funded by the Biotechnology and Biological Sciences Research Council (BBSRC), with additional support from other national and international funding streams, and from industry. We are also supported by the Lawes Agricultural Trust (LAT).
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1Rothamsted Research and the Value of Excellence: A synthesis of the available evidence, by Séan Rickard (Oct 2015)

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The Biotechnology and Biological Sciences Research Council is part of UK Research and Innovation, a non-departmental public body funded by a grant-in-aid from the UK government.
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About LAT
The Lawes Agricultural Trust, established in 1889 by Sir John Bennet Lawes, supports Rothamsted Research’s national and international agricultural science through the provision of land, facilities and funding. LAT, a charitable trust, owns the estates at Harpenden and Broom's Barn, including many of the buildings used by Rothamsted Research. LAT provides an annual research grant to the Director, accommodation for nearly 200 people, and support for fellowships for young scientists from developing countries. LAT also makes capital grants to help modernise facilities at Rothamsted, or invests in new buildings.