Warning from European Academies of Science about implications of neonicotinoid use

Date:04-10-2015

A joint report to the European Commission from the Academies of Science in the EU Member States concludes that there is rapidly increasing scientific evidence that neonicotinoids have a significant negative impact on the natural environment. Some of the organisms affected fulfil important functions in agricultural areas, for example, the wild pollinators and the predatory insects which can play an important role in the biological control of pests. One of the report compilers is Professor Frank Berendse of Wageningen University.

The scientists also conclude that even very low concentrations of neonicotinoids can have a significant impact if they are present in the environment for longer periods. These significant negative effects influence orientation, food-seeking behaviour and resilience to virus infections and parasites, and can eventually lead to the disappearance of species.

The national science academies in the EU have together set up the European Academies' Science Advisory Council (EASAC) with the purpose of providing European politicians with independent advice. EASAC reports are compiled by experts from all participating countries, given an external scientific assessment, and then published only if unanimously supported by the national science academies.

Over the last few years there has been an intensive public debate on whether it is wise to use neonicotinoids. Much of the discussion has focused on real or alleged effects on the honeybee. Various studies concentrating on the honeybee have tended to produce conflicting results. The EASAC report points out that in many ways the honeybee occupies a remarkable position. It is a domestic animal whose welfare and fate is largely determined by beekeepers. Changes in the number of beehives are governed by changes in the environment but also very significantly by socio-economic factors. Another factor is the exceptionally large size of honeybee colonies; this species has a much greater resilience in terms of, for example, the effects of toxic substances than the bumblebees with their much smaller colonies or the smaller, wild bee species which do not form colonies at all.

Although considerable beehive losses have been reported over the last few years, it is difficult to identify an unequivocal, long-term trend in the size of honeybee populations. On the other hand, many of the species found in agricultural landscapes, with an important function in pollination or biological control of pests, have shown a systematic decline in species richness over the last few decades. Examples of such animals are wild bees, hover flies, butterflies, moths, ground beetles and farmland birds. There is every reason, therefore, for shifting attention to these groups and not to focus purely on honeybees.

The report focuses especially on research performed since 2012: laboratory research, greenhouse experiments, field work, and descriptive studies in the field to seek a relationship between concentrations of neonicotinoids in the environment and the presence or dynamics of animal species. Each of these approaches will of course have its own shortcomings. Laboratory experiments take place under circumstances that are often quite different from those in the field, and whereas descriptive studies can certainly demonstrate a correlation, they can never supply conclusive evidence for the actual causes. A large part of the public debate has always focused on the weaknesses of the various approaches. However, the EASAC report concludes that, when taken as a whole, the various approaches certainly show the rapidly mounting evidence for a considerable negative impact on the groups of wild organisms that have an important function in agricultural areas.

The report committee notes that in particular the large-scale, usually pre-emptive, prophylactic use of neonicotinoids in the form of seed coatings leads to unnecessarily high pollution levels in the environment. Most of the toxic substances in the seed coatings enter the soil within a few weeks. This method of pest control shows a marked contrast to earlier EU policy which embraced the principle of Integrated Pest Management, one aspect of which is that pesticide sprays are used only if damage to a crop by, for example, plant lice has exceeded a specific threshold value. 

Europe invests a great deal in restoring natural environments that have disappeared from rural zones. There are now strong indications that neonicotinoid use greatly limits the possibilities for restoration. To summarise, giving permission to use these substances on a large scale does not coincide with earlier EU policy.