In Parliament Square in London today a diverse group of beekeepers and environmentalists are gathering; some will be wearing beekeeping suits, some will be dressed as bees, some will be carrying fruit or vegetables and you may even spot Winnie-the-Pooh with his “hunny”. This is the March of the Beekeepers, organised by a broad range of environmental groups who are pressing for the phasing out of a class of insecticides called neonicotinoids, on the basis that they are harming the health of bees and other insects.
Down here in Devon spring has been very late this year. Our fruit trees are just struggling in to blossom, by my reckoning about three weeks later than normal. On sunny days this week, however, I have seen plenty of bees in our garden: pollen-laden honeybees busying themselves on an ornamental cherry and the plumper bumblebees enjoying the rosemary.
Unbeknown to these creatures, over the winter a battle has raged which may affect their very survival. On one side, a range of environmental groups is arguing for the phasing out of the neonicotinoids and on the other side, the agrochemical companies and the farmers oppose any such ban. Next Monday, the Environment Minister, Owen Paterson will be in Brussels for a key vote that may lead to the banning of these insecticides; the March of the Beekeepers will be urging him to vote in favour of a ban.
The current debate about bees and insecticides was ignited by three scientific studies published in 2012. These studies, conducted under semi-field conditions, showed that neonicotinoids had sub-lethal effects on bee behaviour that impaired survival of bee colonies. The concern has been that these chemicals are contributing to a decline in the numbers of bees and other pollinators. I have written in detail about this in an earlier post but I wanted to discuss two recent developments.
The Environment Minister, Owen Paterson, does not believe there is enough evidence to justify a ban on these chemicals. There have been moves in the EU to ban the neonicotinoids but last month when this came to a vote, Paterson failed to back the ban; there is another vote next Monday. He has also criticised the three 2012 studies showing effects of neonicotinoids on bee colonies: in his view they were laboratory studies and so did not reflect what happens in the field. This is a little disingenuous as the studies actually involved treating bees with neonicotinoids in the lab followed by a field study. To be fair to Paterson, last year he commissioned new work on the effects of neonicotinoids on bumble bees under field conditions. The study took place last summer and the results were released a month ago. The work was done by scientists from the Food and Environment Research Agency (FERA) at York and was a golden opportunity to get the evidence to settle the argument. Let’s take a look at this study.
The scientists from FERA set out to examine the effects of neonicotinoids on bumblebees under real-life field conditions. They selected three fields of oil seed rape: a control field that had not been exposed to neonicotinoids and two others where the oil seed rape had been grown from seed treated with different neonicotinoids (imidacloprid, clothianidin). They placed colonies of bumblebees by the sides of the three fields and followed how the colonies grew; they also analysed pollen and nectar brought back by the bees to determine the kinds of flowers the bees foraged on and how much insecticide they were picking up. As far as I can tell, the FERA scientists expected the bees to forage from the fields of oil seed rape adjacent to their colonies but we are dealing with complex living organisms and the bees (and the crops) had other ideas.
So, what actually happened? First they had problems with the oil seed rape in the imidacloprid-treated field. Here flowering was two weeks late and so the study on this field was deferred for a fortnight. The bumblebee colonies from this field behaved very differently compared to those by the other two fields: they foraged on different plants, they gained less weight and produced fewer queens (although this was not statistically significant). It is difficult to know why the data from this field are so different but they can’t be compared with the other two fields and this certainly messes up the study.
Secondly, when they analysed pollen and nectar from returning bees they found that the bees were foraging on a wide variety of flowers with oil seed rape being only a small (~20%) contributor. This suggests that the bees were mostly ignoring the oil seed rape near their colonies and foraging further away. Analysis of neonicotinoids in pollen and nectar supported this idea and showed that the experimental design was completely wrong. So, for bees next to the clothianidin-treated field, pollen and nectar were devoid of clothianidin but paradoxically they did contain another neonicotinoid, thiamethoxam. For the control “untreated” field, bees also brought back thiamethoxam. To explain these findings we must assume that the bees were ignoring the crops near their colonies and flying to fields and hedges further away and that some of these fields had been treated with thiamethoxam. In fact it is well known that bumblebees fly up to 2 kilometres away from their nests for forage. I don’t understand why the FERA scientists did not take account of this but it means that the study design is meaningless.
Can we take anything from the study? In the conclusion to the report, the FERA scientists note that the bumblebees were unexpectedly exposed to thiamethoxam but their colonies still grew. They conclude from this that under field conditions these chemicals are not affecting bumblebee health. I don’t buy this idea because the experiment is entirely uncontrolled; we have no idea how much thiamethoxam the bees were exposed to or whether this level of the chemical is at all relevant to bee health.
So, if you hear anyone defending this work as providing an answer, don’t believe them. How do we move forward from here? One way is to perform well designed lab-based and field-based studies to address the issues. The alternative is to set up a full field-based study and it has been estimated that this might take up to 10 years and cost £20 million.
In the meantime, there has been another significant development. Over the recent months, several DIY stores in the UK decided to phase out garden products containing the neonicotinoid insecticides. This was an important gesture but about two weeks ago, Waitrose, one of the UK’s leading supermarkets, entered the fray. Waitrose supermarkets are posh supermarkets and they look after you; in many supermarkets the response to the question “Where can I find olive oil?” is “Try aisle 8, mate”. In Waitrose, the assistant will, very helpfully, escort you personally to the part of the shop where multiple kinds of olive oil are displayed. Waitrose is also the Queen’s supermarket; you can see her crest on the Waitrose web site with the slogan “By appointment to Her Majesty the Queen, Grocer and Wine and Spirit Merchant”. Because of this, Waitrose has considerable clout.
Waitrose have decided that farmers supplying the company will, by 2014, stop using three systemic neonicotinoid formulations on crops attractive to bees and other pollinators. Waitrose will also phase these out on their own farms. They have drawn up a seven point plan for pollinators and will fund research at the University of Exeter in to the effects of multiple pesticides and alternative means of pest control.
Up to now, farmers in the UK have been strongly opposed to phasing out these insecticides. Those that supply Waitrose will now have to stop using these chemicals whether they like it or not. If there is significant public pressure, other supermarkets may follow suit. Our Environment Minister is beginning to look out of step with events. The March of the Beekeepers will put more pressure on him. Let’s see what happens when he votes in Brussels on Monday.