'The dose makes the poison' – scientists question neonicotinoid restrictions
The EU Commission’s restrictions on the use of neonicotinoids was put in place in December 2013 and was influenced heavily by studies relying on artificial dosing, which demonstrated sub-lethal effects of the insecticides on honey bees and bumble bees. This research was followed by intensive lobbying from pressure groups who claimed that bee populations were being harmed.
This latest review that questions these artificial dosing studies looks closely at the concentration and duration of the exposure to the bee of the neonicotinoid; it shows that these studies used to justify the restrictions do not reflect the dose to which the bee would be exposed to under realistic field conditions.
One of the often quoted and key pieces of research implicating neonicotinoids is the Henry et al. (2012) paper. The review is critical of this work because of the short duration over which bees were fed doses of neonicotinoid, and uses the analogy that this is like saying the effect of drinking a volume of whiskey over the course of 1 hour is the same as drinking the same volume over the course of 24 hours or longer.
Recent press articles have questioned the approach of some scientists that produced studies implicating neonicotinoids in bees declines
The issue of ‘choice’ is also raised, as the studies implicating neonicotinoids use methodologies that limit the feeding choices of bees, for at least some of the time,to food containing neonicotinoids, whereas in the field, bees generally have a choice of food sources and do not feed exclusively on treated crops.
The review also highlights how the results from a recently published large scale field study, carried out in Canada by Cutler et al (2014), added to other field studies in failing to find any adverse effects on bees exposed to oilseed rape crops treated with the neonicotinoid clothianidin.
While it is obvious that insecticides can kill insects, reviews like this, and others published recently, make it clear that there is still no compelling evidence that under field conditions, the approved use of neonicotinoids is causing significant harm to bee populations.
The NFU has always maintained that the available evidence does not justify the EU Commission’s restrictions of neonicotinoid use, and continues to work to get these restrictions lifted and get evidence-based strategies and measures in place that will actually benefit bee and pollinator populations.