Neonicotinoids are systemic insecticidal substances used in granules, in seed coatings or as a spray. There are currently five active substances in the neonicotinoid family approved at European level. Since the first marketing authorisations were granted for products based on neonicotinoids (in the early 1990s), concerns have been expressed in several countries in Europe with regard to their possible impact on the health of bees.
As of 2012, ANSES on the one hand recommended undertaking a reassessment at European level of the active neonicotinoid substances, and changing European regulations to take more systematically into account the impacts of these substances on the behaviour of bees, and on the other hand called for additional data in the European regulatory framework for the processing of applications for marketing authorisation. In addition, a French Ministerial Order imposes special provisions to strongly reduce the exposure of bees to dust emitted by treated seed.
In 2013, the conclusions of the European Food Safety Authority (EFSA), that had also been instructed to investigate three neonicotinoid substances (clothianidin, imidacloprid and thiamethoxam), led the European Commission to impose a moratorium prohibiting the use of plant protection products based on thiamethoxam, clothianidin or imidacloprid, for certain uses, until 31 December 2015, pending the reassessment of these active substances. This moratorium led to a ban on the treatment of seeds and soils for crops attractive to bees (except crops grown in greenhouses and winter cereals) and also on foliar treatments for crops that attract bees (with the exception of crops grown in greenhouses or after the flowering period).
In line with the measures for the preservation of pollinators and biodiversity implemented by France at European level, ANSES was requested by the Ministers of Ecology, Agriculture and Health to take an active part in the European expert appraisals on the reassessment of the active substances.
It was also asked to indicate whether the new data call into question the uses covered by the marketing authorisations of plant protection products containing one of the five active neonicotinoid substances in France.
Despite a considerable research effort, there is still a substantial lack of knowledge concerning the impact of neonicotinoids on bees. Furthermore, it is not possible to assess the effects on wildlife species from the elements available only for honeybees (especially because of the differences in behaviour between species).
Nevertheless, there are a number of elements available. The ANSES report published in 2015 on the co-exposure of bees to stress factors highlights the multifactorial nature of the causes of mortality of bee colonies, as well as the role of co-exposures to pesticides and infectious agents. Several recently published articles and studies confirm the risks presented by neonicotinoid insecticides for bees and other pollinators, and mainly the three active substances whose use is restricted (thiamethoxam, clothianidin and imidacloprid). There is therefore no reason to lift the restrictions imposed in the framework of the European moratorium.
The available data demonstrate that, in the absence of appropriate management measures, the use of neonicotinoids causes severe adverse effects on pollinator species or those contributing to integrated pest management. In particular they have sublethal effects – that is to say not causing mortality but other effects likely to harm the hive – when these species are exposed to low doses for long periods of time.
Furthermore, this investigation also provided an opportunity to identify the uses for which the risk to honeybees, bumblebees and wild bees is considered to be low, subject to compliance with certain conditions of use. This is the case for example of the uses in permanent greenhouses, on crops not attractive in certain conditions, or when specific management measures are applied. ANSES stresses that it will be necessary to ensure by means of effective controls that management measures are actually applied on the ground.
In contrast, there remains considerable uncertainty regarding a number of uses. These notably concern uses for the treatment of seed for winter cereals. This is because autumn sowing may take place in mild weather conditions, at a period when pollinators are still active and therefore potentially exposed. Uncertainty also remains concerning the levels of residue that can persist in the soil and therefore expose the bees during the following flowering period (treatment by spraying after flowering on orchards and vineyards, choice of crops following those for which the seed was treated, etc.).
In the light of these elements, and pending the results of studies conducted in the framework of ongoing procedures at European level, ANSES advocates strengthening the conditions of use of products containing the active substances clothianidin, thiamethoxam and imidacloprid for all uses for which considerable uncertainty remains. It emphasises the importance of carefully choosing which crops should follow treated crops and advocates planting crops that are not attractive to pollinators following a crop for which the seeds were treated by neonicotinoids.
Finally, it stresses that these recommendations, based on the data currently available, are likely to evolve in the light of the work currently under way in the framework of the procedure for re-approval of substances at European level.