April 29, 2013

expert reaction to EU vote on neonicotinoids

A ban on the the use of neonicotinoid pesticides, which have been blamed for falling bee numbers, has been passed by a vote in the EU. The European Commission will impose a two-year restriction on the chemicals. 

Dr Nigel Raine, Reader in Animal Behaviour at Royal Holloway University of London, said:

“The weight of peer-reviewed scientific evidence suggests that field-relevant exposure to neonicotinoid pesticides can have adverse effects on bees.  Whether this moratorium will benefit bees depends on what alternative methods of pest control are used instead.  If the ban results in greater use of crop sprays the net result could be worse.  More research is needed to determine if this will be the case.  

“There is a clear need to monitor bee populations carefully during the two year moratorium to see whether they bounce back when these three neonicotinoids are not being used.  We also need to check the residue levels of these chemicals in the soil which could persist from crops sown this spring or earlier.

“Bees are actually exposed to multiple pesticides when they forage in the field.  The risk assessment for pesticides needs to take into account this type of combinatorial exposure as well as potential sublethal behavioural effects and longer term (chronic) impacts.

“Insects provide essential pollination services worth at least £440 million to UK agriculture each year.  Pesticides are a critical tool to achieve high levels of crop production.  Both have clear benefits, so we need to ensure that pesticides are used in ways that minimise any detrimental impact on insect pollinators.”

Prof David Goulson, Professor of Biological Sciences at the University of Sussex, said:

“There is no evidence that the withdrawal of these compounds will have significant negative impacts on farming.  It is high time we returned to Integrated Pest Management (IPM) – an approach focussed on minimising pesticide use, maximising the number of biological control agents, using cultural controls such as crop rotations, and monitoring pest numbers so that chemical controls only need be applied when there is a problem.

“Instead, neonicotinoids are applied prophylactically, much like taking antibiotics to avoid getting ill – and this use on crops such as wheat will continue after the partial ban.  This is a recipe for environmental damage and the evolution of resistance in pests.”

Dr Juliet Osborne, Environment & Sustainability Institute at the University of Exeter, said:

“If a moratorium goes ahead, it is crucial that two things take place at the same time to ensure the debate can be properly informed.  

“First, the ongoing review of the pesticide regulatory process must be completed to ensure it is fit for purpose to assess the safety of systemic pesticides.

“Second, a monitoring scheme of wild and managed bees must be set in place to provide evidence as to whether the moratorium is correlated with changes in foraging bee numbers and bee colony mortality.  It would also build a fuller picture if we were able to monitor the effect of such a moratorium on farmers and their crops.

“Whilst not giving direct evidence of cause and effect, such monitoring of bees would fill crucial gaps in the evidence base at the landscape scale, and would be valuable to assess what happens if the moratorium were lifted in the future.  A national monitoring scheme like this would also contribute good evidence to future debates about environmental impacts of land management on bees.”

Norman Carreck, Science Director of the International Bee Research Association, University of Sussex, said:

“It is not yet clear what the implications of this moratorium will be. There has been concern about this class of insecticides ever since they were introduced twenty years ago, yet many experiments and wide-scale studies in many countries over the years have failed to demonstrate harm to bees in the field. This being the case, it will be very difficult to demonstrate any benefits to bees of a moratorium in just two years.

If the purpose of the two years is to enable scientists to gather definitive evidence of the effects in the field, it is hard to see how can this be done if fields will no longer use treated seeds. I am also concerned about what Environmental Impact Assessment has been carried out to evaluate the effects on bees of the use of alternative pest control measures that will follow this moratorium. Neonicotinoids will inevitably be replaced by older compounds. Just as we lack knowledge of the subtle sub-lethal effects of neonicotinoids in the field, we know little about these other compounds either, because historically the registration process has not focussed on these aspects.”

Dr Lynn Dicks, Research Associate at the University of Cambridge and NERC Knowledge Exchange Fellow, said:

“This is a victory for the precautionary principle, which is supposed to underlie environmental regulation. Scientific evidence is unclear about the role neonicotinoids play in causing declines in bees and other flower-feeding insects. They are probably one of many interacting threats, so a broader approach to protecting insects would be better. But neonicotinoids are one factor that MIGHT be causing a serious problem. The precautionary principle says we should err on the side of caution and stop using them while we find out more. I hope the EU Member States will now consider monitoring patterns of pesticide use more closely”

Prof Lin Field, Head of Biological Chemistry and Crop Protection at Rothamsted Research, said:

“We are concerned that the decision has been made through political lobbying, rather than a comprehensive and sound scientific risk-benefit assessment.  There are many other factors known to affect bee colonies – the varroa mite, the bee viruses spread by the mites, pesticides that beekeepers use to kill the mites, climate effects and flower and nectar availability – all of which need to be taken into consideration.  Thinking we can solved the bee problem by a ban on neonicotinoids may mean we overlook these other important factors.

“What’s more, the decision does not take account of the risk of the ban on our ability to control insect pests and secure crop yields.  Securing, and indeed increasing yields for food security, is a priority in Europe and will require a crop protection strategy to avoid unnecessary losses.  At present and until we find reliable and effective alternatives, the control of insect pests (and the crop diseases they carry) will rely on the use of chemical insecticides and banning neonicotinoids will reduce our options. 

“A major biological risk of removing an entire chemistry is that resistance will develop against the remaining products.  This is exactly what has happened in human health with bacterial antibiotic resistance.  Or are we willing to accept lower yields, leading to greater imports and potentially higher food prices?  The UK has already become a net importer of wheat this year for the first time in a decade.  It has also been reported that a ban on neonicotinoids could result in a significant impact to UK oilseed farmers, costing the UK economy £630m each year.

“That said, we should not ignore the potential implications of pesticide use on pollinators.  Rather than an immediate ban, we should take this opportunity to further study and de-convolute the many possible causes of colony collapse and aberrant foraging behaviour.  This will then help us to balance the risks and benefits for crop protection, crop pollination, ecosystem function and our health appropriately.”