In 2013 the EU issued instructions withdrawing the use and sale of three neonicotinoids, namely imidacloprid, thiamethoxam and clothianidin, due to concerns about their potential impacts on bees. The UK government did not support this ban because the scientific evidence was not deemed adequate. The EU will shortly be reviewing the evidence and the ban, and will be announcing their revised position soon. Please look out for HTA updates and for any news on their website.
Neonicotinoids have been widely adopted because of their effectiveness in treating insect pests and their favourable human and environmental safety profile, especially when compared to the older products they replaced. They play a critical role in modern integrated pest management programs by targeting specific pests while helping to preserve beneficial insects. With hundreds of studies conducted, we know more about neonicotinoids and bees than about any other class of insecticide.
A number of neonicotinoid products that pose little or no harm to beneficial insects or bees are still available for amateur sale including Multirose, Provado, Bug Clear and Rose Clear (please see table below for full list).At present it remains legal to continue to sell these products. These products have been fully assessed and rigorously tested and carry very clear instructions for safe application. Customers may ask about their safety and the danger to bees and there is currently insufficient scientific evidence to form a clear informed opinion on this. This is the view held by the government, HTA and NFU. We are all engaged in Defra's National Pollinator Strategy and everyone acknowledges the need for more research to be carried out. This includes research into alternatives to neonicotinoids.
The term "neonicotinoid" covers a wide range of products used in insect control, with just three on the EU banned list and most of the studies that have been carried out have been based on products used by field scale agriculture not in ornamental crop production. Many of the arguments about the products' use have no relevance to ornamental production methods or even relate to the products used by ornamental growers. However the impacts of their withdrawal have led to significant and highly damaging populations of vine weevil populations in nurseries with many growers reporting increased losses this year and increasing costs in having to resort to alternative controls.
Neonicotinoids are traditionally applied in ornamental horticulture as a soil drench in the autumn to protect against over wintering larvae and the most widely used one involved a single treatment that was effective for six months. These treatments were applied under the protection of closed glasshouses. Since the ban was imposed the adult weevil population has been able to multiply and wreak havoc on plant stocks.
On Wednesday 8 April 2015, a study from the European Academies Scientific Advisory Council, entitled ‘Ecosystem services, agriculture and neonicotinoids' was published in Nature magazine. The report suggests there is "an emerging pollination deficit,". Critics of this report point out that it refers to old studies and not new evidence and gives undue weight to laboratory work rather than field studies. Furthermore, the panel of experts are an invited group of which no UK establishment would appear to have been represented.
A further two pieces of research have since been published in Nature. These were carried out under the auspices of the National Pollinator Initiative. The first reports on a field-based piece of research on seed-coated treatments and wild bee populations. The second piece of research looked at honey bees feeding behaviours. In both cases the research is not sufficient to demonstrate a clear causal link and the findings are equivocal.
None of this research suggests any link between the use of neonicotinoids in ornamental production methods and impact on pollinators.
Furthermore the research carried out to date appears to overlook the many environmental factors affecting bee health. EU research in 2013 points to diseases, varroa mite and American Foul Brood being the strongest factors, as the graphs below show.
The HTA will continue to fully support the work and aims of the National Pollinator Initiative and the commitment to researching the science behind neonicotinoids and pollinator health. However, on balance, the jury is still out on whether the research carried out to date has carried the understanding much further forwards than before. In addition more work remains to be done on wider environmental causes of bee decline and research into alternative controls to limit the damage currently being suffered by growers.
The EU has recently announced that it will start a review of the evidence towards the end of May 2015 and we will continue to monitor developments. The European Commission's original proposal included an exemption to allow treatments on bee attractive crops in greenhouses after flowering and we will continue to argue for a full exemption for ornamental horticulture for autumn treatments as well.