Common pesticides a threat to bees, EU watchdog says

Three widely-used pesticides made by Switzerland's Syngenta and Germany's Bayer pose an acute risk to honeybees, the European Union's food safety watchdog said on Wednesday (16 January), but stopped short of linking them to bee colony collapse.

Fears over the effects on bees of neonicotinoid insecticides – among the most commonly used crop pesticides in the world – led France to withdraw approval in June last year for Syngenta's Cruiser OSR, used to treat rapeseed crops.

Responding to the opinion by the European Food Safety Authority (EFSA), the European Commission said it was ready to take the necessary steps if its findings are confirmed, raising the prospect of EU-wide restrictions on the use of the products.

As EURACTIV reported in November, EFSA  launched a review of scientific studies and risk assessments in response to the decline in bee populations worldwide and in Europe.

The three pesticides analysed by EFSA were clothianidin and imidacloprid, both of which are primarily produced by Bayer's agricultural unit Bayer CropScience, and Syngenta's thiamethoxam, the active ingredient in Cruiser OSR.

EFSA said harmful pesticide residues in the pollen and nectar of plants treated with the three chemicals meant that they should only be used on crops not attractive to honeybees, such as sugarbeet. That would exclude their use on maize, rapeseed and sunflower crops.

Bees also face an acute risk from exposure to drifting pesticide dust following sowing of cereal seeds treated with the chemicals, including wheat and barley, EFSA said.

However, the EU scientists found no link between use of the pesticides and the phenomenon known as bee colony collapse disorder, which has seen bee populations fall rapidly in recent years across Europe and North America.

"Due to shortcomings in the data, EFSA was unable to finalise assessments for long-term risks to colony survival and development … and therefore conclusions could not be drawn on colony collapse disorder," the opinion said.

Industry response

Bayer CropScience said in a statement it did not believe EFSA's findings altered the conclusions of previous EU assessments of its products, which found no unacceptable risks in their use.

"It is very important that any political decision relating to registrations of neonicotinoid-containing products should be based on clear scientific evidence of adverse effects of the affected products under realistic conditions of use," the statement said.

A study by Britain's Food and Environment Research Agency said last year that there was no evidence that use of neonicotinoids could cause the collapse of whole bee colonies.

EFSA said current gaps in the scientific data meant it had been unable to assess the risks posed to bees by some of the authorized uses of the pesticides, and there was a high level of uncertainty in its latest evaluation.


Garlich von Essen, secretary-general of the European Seed Association (ESA), said of the EFSA report: “EFSA focusses on quite theoretical, potential risks to bees, and identifies a number of perceived data gaps. Yet, the requirements to generate such data did not exist upon the time of authorisation and are not even part of an agreed and published standard today.”

ESA said in a statement that the information from other independent research was "largely disregarded".

“These findings demonstrate that identified potential risks can be managed and are being managed through established stewardship and good agricultural practices. It seems that this information has not been taken fully into account – but maybe that is due to the quite tight timeline within which EFSA had to deliver this report.”

Pesticide manufacturers seized on the uncertainty in EFSA's findings, and said the opinion provided no grounds to challenge the currently approved use of the chemicals.

"Restricting neonicotinoid pesticides on the basis of potential risks will do nothing to improve overall bee health but would do enormous damage to farming and food production in Europe," Friedhelm Schmider, the head of European pesticide lobby ECPA, said in a statement.

A report published on Tuesday (15 January) - commissioned by ECPA and the EU farmers' association COPA-COGECA - found that current treatment of seeds using the three pesticides boosted EU commodity crop revenues by more than €2 billion a year, and said that 50,000 farm jobs could be lost if the products were banned.


The EU-funded STEP project recommends several ways farmers can protect bee populations:

  • Try to avoid those pesticides known to have negative impacts on bees;
  • Reduce the use of herbicides which suppress flowering plants;
  • Leave uncultivated flower rich patches in farmland where pollinators can benefit from flowers and nesting resources;
  • Plant mass-flowering crops (oilseed, clover and field beans) as part of rotations to provide extra nectar and pollen for bees and other insects.

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