Searching for blog posts tagged with 'neonicotinoid'

The neonicotinoid saga continues

Jun

15

Yesterday saw publication of my review of the evidence for broader impacts of neonicotinoids on wildlife other than bees in the Journal of Applied Ecology. If you'd like to read it, please go to Goulson Lab publications page, scroll down, and click on the link to the pdf.

The key points are as follows:

1) Neonicotinoids are very widely used, and have extremely high toxicity to all insects and many crustaceans. They are commonly applied as a seed dressing to crops.

2) Most (<90%) of the active ingredient do NOT go into the crop, but get washed into the soil and ground water. They also leach into streams. Levels found in streams and California and the Netherlands commonly exceed lethal concentrations for aquatic wildlife. Data from UK waterways appear to be absent.

3) They have a half life in soil which commonly exceeds 3 years, meaning that they rapidly accumulate in soil if they are used annually. The effects of this on soil organisms and soil health are not understood.

4) Neonicotinoids have been found in field-margin vegetation, which is hardly surprising if they are accumulating in soils. Impacts of this on farmland wildlife such as butterfly caterpillars feeding on field margin vegetation have not been studied.

5) If dressed seeds are consumed by granivorous birds such as partridge, or by rodents such as voles, they need only eat a few seeds to recieve a lethal dose. During drilling, seed is inevitably spilled, but we do not know whether it is consumed by wildlife.

6) Evidence that neonicotinoid seed dressings actually increase yield is absent (or is not available for public scrutiny). Some US studies suggest that they have negligible benefit to farming. In short, modern farming practices do not seem to be EVIDENCE BASED, but are driven by marketing by the agrochemical industry.  

7) We seem to have forgotten all about Integrated Pest Management (IPM), an approach which emphasizes minimising pesticide use through monitoring of pest numbers, crop rotations, encouraging natural enemies etc... Instead we are simply using pesticides prophylactically.  

Although I supported the 2 year moratorium on use of neonics, which comes into effect in December 2013 (better than nothing), it is entirely unclear what it will achieve, or what will happen afterwards. Neonics will continue to be used extensively for non-flowering crops such as winter wheat. Even if we completely stopped using them they would be in soils for years to come. So any benefits from the partial moratorium will not be apparent in 2 years. In any case, there seems to be no plan to monitor the benefits, so if they did occur (which is unlikely) we wouldn't know.....

It is hard for most of us to make sense of what is going on here.....

 Dave Goulson's research lab website

 

  

 

Biggest bumblebee poisoning event in history

Jun

22

On 15 June, a landscaping company in Wilsonville, Oregon, decided to spray some lime trees with insecticide. The trees were in a parking lot, and had some aphids on them, so there was a risk that some cars might get little drops of sticky honeydew on them. Faced with such a dire threat to the future of humanity, it was only natural and reasonable that the company should blitz the trees with Dinotefuran, a type of neonicotinoid insecticide.

On 22 June, Saturday morning shoppers reported the car park to be blanketed in dead bumblebees; about 50,000 at the latest count. The trees were flowering, and bees love lime nectar. The dose of pesticide they received from the nectar was clearly enough to kill many of them almost instantly, for they fell dead beneath the trees, the biggest recorded bumblebee poisoning event in history. Perhaps many more staggered off to die elsewhere.

For me, this highlights the utter stupidity of allowing pesticides to be used for cosmetic purposes, in gardens and parks. Using pesticides in farming can be justified by the need to grow food efficiently; we all need to eat. But do we need to be able to pop to the local garden centre or supermarket and buy bottles of highly toxic compounds advertised for use on roses and other flowers? In towns, councils routinely spray herbicides and insecticides for no real purpose, other than to make the streets look a little tidier, or the grass in the park look a little greener (and a little more toxic).

Why don’t we ban pesticides in urban areas, and turn our cities into havens for wildlife?

Toronto has banned such chemicals within the city limits. The city hasn’t been over-run with pests. People still have pretty gardens, and grow healthy vegetables. The parks look just fine. If they can do it, why not the rest of us?

Back in Oregon, the Xerces Society, an organisation devoted to insect conservation, have attempted to enclose the poisoned limes with netting to keep bees out. But they are concerned that the poison may stay in the trees for years, since neonicotinoids are very long lasting, so they may poison bees for years to come.

One wonders how many similar incidents escape attention because the bees do not die in such an obvious place. “Wild bees are killed all the time in agricultural fields where nobody sees it happen,” said Mace Vaughan of the Xerces Society. “The fact that this happened in an urban area is probably the only reason it came to our attention.”

Isn’t it high time we stopped poisoning our bees?

 

 

Monarch butterflies; A&E conservation not the way forwards?

Jan

02

Monarch butterflies are one of the most beautiful and remarkable of insects. They migrate annually from cool forests in the mountains of Mexico, where they hibernate in vast numbers, northwards to all of the USA and into southern Canada, where they breed on milkweed plants. Somehow their descendants, reared in North America, know exactly where to return in the autumn. Once a common sight, sadly monarch numbers have plummeted in recent years. The cause isn’t known for sure – it may be a lack of habitat, particularly a shortage of milkweeds, which are widely considered to be noxious weeds and targeted with herbicides. It may be insecticides; some, such as neonicotinoids, disrupt the ability of insects to navigate at unimaginably small doses.  Or it may be a combination of the many stresses that the modern world throws at these marvellous creatures.

The news has recently highlighted conservation campaigns in North America which are encouraging people to grow milkweeds in their gardens, and which are trying to sow wildflower mixes including milkweeds along road verges. This is of course laudable, certainly better than doing nothing, and it just may work; conservation efforts focussed on specific, charismatic (usually large and beautiful or cute) creatures do sometimes succeed. But something about this makes me deeply uneasy. It seems to me that this is a bit like applying a sticking plaster to someone who has just been run over by a lorry. There are perhaps 5 million species in the world, maybe more. The current rate of extinction is thought to be roughly 1,000 times the natural rate, with perhaps ten species going extinct every day. Most have never even been named, let alone received a concerted conservation campaign. We cannot possibly save them one species at a time.  

So what is the answer? There is no simple one. Somehow, we need to set aside more land for wildlife. We need to find ways to farm that also support biodiversity – at present, most methods of farming across the globe are disastrous for wildlife. But how do we do that and feed the ever growing human population? Most governments are obsessed with economic growth, government-funded agricultural research mostly focusses on intensifying farming and increasing yield, and most agriculture is owned and run by vast industrial enterprises focussed on short-term profit. While we continue down this route, global biodiversity is doomed to rapid erosion, until only the toughest, most adaptable creatures persist. Of course in the long term, this will reduce the ability of the planet to support us, and our descendants will be doomed to a miserable existence. Already soils covering an area the size of India have been badly degraded through intensive farming, and climate change threatens to make further vast areas uninhabitable.    

There is an alternative. For a start, if we all ate less meat and reduced the spectacular levels of food wastage (at all stages of the chain from the farm to the domestic fridge) we would need to grow an awful lot less food, and that could go a long way to solving the problem. More broadly, we need to somehow stop the endless drive for ‘growth’, given the obvious point that we live on a planet of fixed size with finite resources.

The Earth is roughly 1,000 billion miles from the nearest planet that might possibly support life. It is quite probable that we will never be able to get there, and that we may never be visited by extra-terrestrial life, if it exists. So shouldn’t we look after the only planet we have, and the unique creatures that live here with us? Helping monarchs is all very well, but band-aid measures for a few unusually pretty animals are not going to save the planet.      

PS Anyone who knows me may well feel the need to point out a certain hypocrisy; I’ve been involved in several conservation campaigns focussed on single species, such as the short-haired bumblebee reintroduction in SE England. I’m not saying that we shouldn’t do these things – sometimes it is all that we can do, as individuals. Such programmes can do widespread good; the short-haired bumblebee project has resulted in lots of new flower-rich glasslands, great habitat for many species. Perhaps the monarch campaign can do the same. But a broader, holistic approach to managing the planet is needed if we are to make any significant dent in the collapse of global biodiversity.

Dave Goulson's research lab website

  

USA finally considering action over neonicotinoids, spurred on by doubts as to whether they actually work

Jun

02

Two US Congressmen have launched a bill to suspend uses of neonicotinoid insecticides in the US, following the lead of the European Union. Representatives John Conyers of Michigan and Earl Bluemenauer or Oregon introduced the “Saving America’s Pollinators Act”. They were prompted by widespread honeybee colony losses and a major bumblebee kill in Oregon where 50,000 dead bumblebees were found beneath two lime trees as a result of their being sprayed with neonicotinoids for ornamental reasons (note that lime trees often have a few dead bumblebees under them for separate reasons that have never been fully explained). I was recently invited over to speak in Capitol Hill in support of this bill.   

The debate over neonicotinoids and bees rolls on and on, with new studies emerging every day. It seems to me that the evidence on bumblebees is clear and convincing - realistic doses are very likely to be doing harm to wild colonies – but the evidence for honeybees remains muddier. However, most of the studies finding no impact on honeybees have been funded by or performed by the industry that manufactures the chemicals, so murky waters are to be expected. 

My visit coincided with the launch of a fascinating review of the economic value of neonicotinoids, produced by the Centre for Food Safety, a US-based non-profit organisation. They review 19 studies that have evaluated how much neonicotinoid seed dressings (the usual way of using these chemicals) increase yield of a range of crops, including wheat, corn, soya beans, and oilseed rape. The findings are astonishing – in every case, the studies either found no benefit whatsoever, or weak and inconsistent benefits unlikely to offset the cost of the pesticide. As Dr Christian Krupke (a leading researcher on this topic at Purdue University) said to me, “There may be places in the US where the pests are so bad that farmers need neonicotinoid seed dressings, but we can’t find them”.

In short, the most widely used pesticides in the world - prophylactically applied to arable crops across the globe - appear to be ineffective, and to have been widely miss-sold. It reminds me a little of the Payment Protection Insurance scandal – farmers are advised to use seed dressings as an insurance against something which, it seems, almost never happens.

Remarkably, no similar studies seem to have ever been performed in the UK or elsewhere in Europe to evaluate how much, if at all, neonic seed dressings increase yield here. It would be easy to do – experimental plots of crops that are treated exactly the same, except for the presence or absence of the seed dressing. How did these chemicals come to be so widely used without the manufacturers demonstrating clearly that they worked? If they did perform such studies, why can nobody find them? Sceptics such as I might also point to Italy, where neonics were banned on corn some years ago and where yields have remained stable and corn farming profitable.   

For me, this turns the whole bee debate on its head. If neonic seed dressings were essential to grow crops, one might have to accept a risk of harm to bees. But it seems that they are not.

In Europe, a decision will need to be made in the next year or so as to whether the current EU moratorium is extended or allowed to lapse. This new evidence will hopefully help to prevent the latter.

Prof Dave Goulson, University of Sussex.

[An abbreviated version of this Blog is published in the newsletter of the BBKA, June 2014]

Are crops being devastated without neonicotinoid protection?

Oct

10

Response to article by Matt Ridley in the Times, 6 October. Note that the Times refused to publish a (shorter) response that I sent to them:


To: letters@thetimes.co.uk

 

Dear Sir,

 

On 6 October, the Times published an opinion piece by Matt Ridley on the impacts of the neonicotinoid moratorium on farming. These insecticides are the subject of a partial 2 year ban introduced by the EU because of the perceived risk they pose to bees. Ridley asserts that oilseed rape crops are now being devastated because they are not being protected by these insecticides, claiming that in some regions up to 50% of the crop has been lost. He argues that there is “literally no good science linking neonics to bee deaths in fields” and that the moratorium only came about because “green lobby groups… have privileged and direct access to... European officials”. He goes on to claim that there is no evidence that bees are declining, and that they will be worse off if there is less oilseed rape for them to feed on as a result of the moratorium. He even sneaks in a quick go at badgers, suggesting that they may be the main problem that bumblebees face. In short, he says the moratorium is a typical barmy bit of EU legislation that is crippling farming for no good reason, no better than the apocryphal EU restrictions on the shape of bananas.

 

I’m one of the scientists who have been conducting this “no good” science, so you might not be surprised to hear that I have a rather different view of the situation. The EU decision was taken only after a team of scientists at the European Food Standard’s Agency had spent 6 months reviewing all the scientific evidence. They concluded that neonics pose an “unacceptable risk” to bees, and hence a majority of EU counties voted for the moratorium. The UK’s Environmental Audit Committee, a cross-party group of MPs, came to the same conclusion, and urged our government to support the ban. The US Fish & Wildlife Service also concurred, and have banned use of all neonics on land they administer. Most recently, a team of 30 scientists, of which I was one, reviewed 800 papers on this topic and in a series of 8 articles published in the journal Environmental Science and Pollution Research, concluded that “The combination of prophylactic use, persistence, mobility, systemic properties and chronic toxicity [of neonicotinoids] is predicted to result in substantial impacts on biodiversity and ecosystem functioning”.

 

These neurotoxins persist in soils for years, and they are now known to be found in hedgerow plants, streams and ponds. One teaspoon is enough to deliver a lethal dose to 1.25 billion honeybees (it would kill half of them, and leave the others feeling very unwell).  But they do not just pose a threat to bees; any insect living on farmland or in streams that flow from farmland, and any organisms that depend on insects for food (e.g. many birds and fish) are likely to be affected.

 

The backdrop to all this is that over the last 60 years arable farming has become highly dependent on a blizzard of chemical inputs. Many crops are treated with twenty or more pesticides each year, and grown in vast monocultures with minimal use of rotations and negligible attention paid to encouraging natural enemies that can help to control pests.

There is little space left for nature. As a result, European wildlife populations are collapsing. RSPB’s 2013 “State of Nature” report summarizes the state of play, and it is bleak reading – most farmland wildlife groups for which we have data are overwhelmingly in decline. According to British Trust for Ornithology data, 44 million breeding birds vanished from the British countryside in the last decades of the 20th century.  

 

Conservation organizations are fighting a losing battle. To claim that they have “privileged” access to politicians is bizarre; never have green politics been so low on the agenda. It seems rather more plausible that those who profit from promoting intensive farming, particularly the agrochemical industry, are the ones with access to regulators and policy makers. Sales of neonics alone are worth $3billion pa, so that industry can afford to employ armies of lobbyists. Many EU countries have folded under pressure from industry and allowed farmers derogations to use neonics during the ban. Following the recent stories of oilseed rape losses in the UK, Defra have allowed farmers to spray different types of neonics onto their crops, while others have resorted to sprayed their rape seedlings up to 5 times with pyrethroid insecticides already this autumn, at the same time complaining that pyrethroids don’t work because the pests are resistant (so why use them?). In these circumstances the moratorium is worse than useless, but surely there is a better, more sustainable way forwards? We need to find ways to grow crops without damaging the environment. If rape cannot be grown in some areas without blitzing it with neurotoxins, then perhaps farmers should consider growing something else entirely? If they tried to wean themselves off their chemical dependency, introduced more diverse crop rotations, left small areas for wildlife, and tried to encourage natural enemies of their pests, they might find that their problems got better.

 

What of Ridley’s claim that oilseed rape crops are being wiped out because they are no longer protected by neonicotinoids? He is not the first to say this. In May, the NFU Vice President Guy Smith claimed on Farming Today that 70% of the Swedish spring oilseed rape crop had been wiped out by pests following the introduction of the neonic moratorium. This was wildly incorrect – when eventually official figures emerged, the yield was down just 5%. Two days ago Defra revealed official figures on the extent of the damage in the UK – 1.35% of the crop has been lost (http://www.hgca.com/press/2014/october/08/csfb-crop-losses-estimated-at-27-in-hgca-funded-%E2%80%98snapshot-assessment%E2%80%99.aspx). Note that some crops are lost every year, with or without neonics. So why would a senior politician (Matt Ridley is a tory Lord and brother-in-law to Owen Paterson) and VP of the NFU want to grossly exaggerate the damage, and hence by implication suggest that farmers cannot grow crops without neonics? This is not in the farmer’s best interests, or that of the environment, or that of consumers. One might be forgiven for wondering if they weren’t actually working for the agrochemical industry.

 

Finally, will bees suffer if farmers grow less oilseed rape because of the moratorium, as Ridley asserts? I doubt it. Bees need a steady supply of food through the year, not a four week spring glut followed by famine because there are few wildflowers. In any case, if you were offered a feast of food laced with a neurotoxin, or a more modest meal of unpoisoned food, which would you opt for? In a sense, that is the choice that we all face right now.

 

Dave Goulson is Professor of Biology at the University of Sussex. He is author of the bestselling A Sting in the Tale and A Buzz in the Meadow, the latter describing the neonicotinoid controversy.

 

“Bee Informed” – but not by this propaganda

Apr

26

 

Pop in to your local Homebase, find the long aisles where the plethora of garden pesticides are arrayed, and you will now find glossy leaflets prominently displayed with a picture of a bumblebee on the front, entitles “BEE INFORMED - WHEN USING INSECTICIDES IN YOUR GARDEN”. So far so good, I can’t really argue with that. But read on.

Inside the leaflet, you will learn that bees are important. Excellent stuff. Then you will be told that bee health has been compromised, and that “A number of culprits have been identified, including:

• Parasitic mites such as Varroa

• Bacterial, fungal and viral diseases

• Habitat loss and degradation

• Genetic factors”

All true, but you might be thinking that there is an obvious omission from this list. Read on, and you will learn that “Some claims have also been made of a possible link between the decline in bee populations and the use of some insecticides. This has not been shown scientifically”. Hmmm.

The “some insecticides” they refer to are presumably neonicotinoids, the controversial chemicals that have been at the heart of a ferocious debate for ten years or more. Neonicotinoids are the active ingredient in many garden insecticides, and you may well also drip them on the neck of your dog or cat to prevent fleas. A group of scientists at the European Food Standards Agency spent six months examining the safety of these chemicals, and concluded that they pose an “unacceptable risk”. As a result, a majority of European countries voted for a ban on several of the most widely used neonics on flowering crops that bees might visit (the UK government opposed, of course). Since then, a huge review of over 1,000 scientific papers was written by 28 scientists from all over the world (I was one), under the auspices of the International Union for the Conservation of Nature, and it concludes that neonics are harmful to bees and pose a serious threat to biodiversity. On top of that, The European Academy of Sciences published a huge report on the subject last year, written by a team comprising a leading scientist from every European state. Their findings echoed the earlier reviews; these chemicals are damaging to bees and other wild insects. None of this is particularly surprising; these are highly poisonous neurotoxins that kill insects of any sort in minute, near-infinitesimal doses. They are also highly persistent, sometimes lasting for years in soil and plants.       

So who produced this wildly misleading leaflet? The Crop Protection Association, the Horticultural Trades Association, and the British Beekeepers Association (BBKA). The first two come as no surprise; these are essentially wings of the agrochemical industry, pushing their poisons as usual. But the BBKA? Really? Shame on you.

The leaflet goes on to say that “Provided that garden care products are used as directed on the label, they will not pose a problem to bee health.” Yet a recent Swedish study, published in the most prestigious scientific journal in the world (Nature), showed huge impacts of neonics on bumblebees and solitary bees when the chemicals were used by farmers ‘as directed on the label’. Remember that, 50 years ago, the agrochemical industry assured us the DDT was safe, until it turned out that it wasn’t. Later, they told us that organophosphates were fine, except they weren’t. Do you believe them this time? I don’t. 

The simple truth is that none of the array of chemicals on sale in your local garden centre are necessary. I have a two acre garden that I manage singlehandedly, while having a full-time job, and I manage to grow heaps of flowers and veg. It isn’t the tidiest garden ever, but it looks wonderful (to me anyway!). Every year my broad beans are attacked by a horde of black bean aphids, but after a week or two an army of ladybirds, hoverflies, lacewings and tiny parasitoid wasps come to the rescue, and in no time they are gone. The bean plants look a bit dog-eared, but they recover and give a great harvest. No need for insecticides. I’m ashamed to admit I used to use glyphosate, and I still have an old pot of it in the shed still, but since the World Health Organisation announced that it is highly likely to be carcinogenic[1] I have stopped using it. Hoeing works just fine, and I have kids and pets in the garden.   

To be honest, I expect nothing else from the pesticide industry. They are a hugely powerful and rich lobby that spends a fortune trying to convince us that we need their products. But why does Homebase push their propaganda? I guess money is the answer. Why does the BBKA support it? Do their members agree? I’m pretty sure that most of them don’t. The senior management of BBKA have always had an oddly cosy relationship with the agrochemical industry, to the horror on many of the BBKA members who I have spoken to. I guess that money has changed hands at some point.

The leaflet also mentions the Royal Horticultural Society as a source of further information, though it is not clear if RHS endorse it. I sincerely hope not.

We should boycott Homebase until they stop displaying this leaflet (my boycott started today, but on my own I don’t think that will bring them to their knees). We should campaign for these chemicals to be withdrawn entirely from garden use. I would love to see ALL pesticides banned for use in the garden; there is just no need, no need at all.  

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The leaflet can be downloaded from the Crop Protection Association directly here:

http://www.cropprotection.org.uk/media/31346/bee_safe_leaflet_v13_final_final_jan_12.pdf 



[1] Glyphosate, a herbicide, is the most widely used pesticide in the world. It is in most foods we eat. Recent studies have found significant levels of glyphosate in urine of almost every German of 2,000 tested, with the highest levels in children.  

Will the UK retain the neonicotinoid moratorium post-Brexit?

Oct

14

A couple of weeks ago the Society of Chemical Industry held a meeting in London to discuss “Are neonicotinoids killing bees?” As you might guess from the name of the people organising it, this seems to have been a rather one-sided affair; a bunch of lobbyists from the agrochemical industry, and a hand-picked selection of scientists consisting overwhelmingly of those known to have pro-pesticide leanings and/or receive funding from the agrochemical industry. I was unable to attend this travesty of a meeting, but I did get a chance to hear how it was reported on BBC Radio 4’s Farming Today, and BBC gave me two minutes to give an off-the-cuff response to comments made by two attendees, Norman Carreck[1] (of Sussex University and the International Bee Research Institute) and Peter Campbell (of Syngenta). Here I give a slightly more detailed and considered response.

            Norman’s summary can be paraphrased as “It is all complicated and confusing, we can’t really be sure what harms bees. The moratorium on neonic use on flowering crops[2] is forcing farmers to use older, nastier chemicals that we know little about. This could be worse for bees than using neonics”. Peter stated categorically that in real world situations neonics don’t harm bees. He pointed to an authoritative Swedish study, the largest field trial yet performed to examine the effects of neonics on bees, which found no effect on honeybees of placing their colonies next to a treated oilseed rape crop for one year (Rundlof et al. 2015). Any politician listening to this would be inclined to think that the scientific evidence against neonics is far from clear, and that the current moratorium might be doing more harm than good. Of course this is exactly what the meeting was intended to achieve – job done. The pesticide industry makes billions of dollars every year from these chemicals, and spreading doubt and confusion is a great tactic to prevent policy makers from taking further action, and to encourage a post-EU UK government to abandon the moratorium altogether.

            Let’s look at what we actually do know with certainty about neonics:

1) These are very widely used neurotoxins, applied extensively to many arable, horticultural and ornamental crops, and also found in veterinary products such as flea treatments for dogs and cats. They have high persistence so last for years in soil (Goulson 2013; Bonmatin et al. 2015). They are water soluble and are now routinely found in streams and ponds around the world (Bonmatin et al. 2015). They are also found in the pollen and nectar of wildflowers growing near treated crops (Botias et al. 2015; David et al. 2016), as well as in the pollen and nectar of the crop itself.

2) When we place honeybee or bumblebee nests onto farmland, the pollen and nectar stores that they gather often contain a cocktail of several neonics (and a bunch of other pesticides, mainly fungicides). Concentrations of neonics in their food typically range from 1 to ~10 ppb, sometimes more (which of course means that your breakfast honey also likely contains these neurotoxins) (Botias et al. 2015).

3) If we dose honeybees or bumblebees in the lab or in cages with food spiked with these same concentrations of neonics (i.e. between 1 and 10ppb), we get the following range of effects: reduced longevity, impaired immune response, impaired learning, reduced egg laying in queens, reduced fertility in males (reviewed in Pisa et al. 2015; Straub et al 2016). [Note that not every single study finds the same effects and a few have found no effects, presumably due to differences in methods, the particular neonic and dose used, the age and health of the bees used, the bee species studied etc. It isn’t simple, but the overwhelming evidence is that neonics do harm bees at field-realistic doses]

4) When bumblebee colonies are exposed to field realistic doses (Whitehorn et al. 2012; Arce et al. 2016) or exposed to treated crops in a field setting (Goulson 2015; Rundlof et al. 2015), the colonies perform very poorly, grow slowly and produce few queens.

5) Solitary bees perform poorly when near treated crops; fewer wild bees are found on the crop itself, and Osmia bees fail to nest entirely near treated crops (Rundlof et al. 2015). 

6) Declines of wild bees and butterflies in the UK strongly correlate with geographic patterns of neonic use (Woodcock et al. 2016; Gilburn et al. 2015). [The pesticide industry immediately respond to this by saying “correlation is not proof of causation”. Of course this is also what the tobacco industry said about cancer and smoking. Correlation is not proof, but it is good confirmation of other evidence]    

7) When honeybee colonies are exposed to treated crops, the deleterious effects on individual bees described in (3) do not seem to translate into significant harm to the colonies, at least inside a single year (e.g. Pilling et al. 2013; Cutler & Scott-Dupree 2007; Rundlof et al. 2015). Note that all but one of these studies (Rundlof et al. 2015) were performed by the agrochemical industry themselves or funded by them, and thus should probably be treated with a pinch of salt. If we take them all at face value, this does not rule out the possibility that exposure to neonics might contribute to colony loss in the longer term, for example by reducing queen longevity/ fecundity, but it does seem that there is no dramatic and immediate effect on honeybee colonies in the way that there is with bumblebees and solitary bees. Perhaps the very large colonies of honeybees buffer them against the impacts of pesticides, at least in the short term.  

Overall, the case that neonics harm bumblebees is iron-clad. There are dozens of studies from lab to full field experiments that provide a convincing and coherent body of evidence. The case that neonics cause honeybee colonies to die has not been proven beyond doubt, though it would seem highly likely that having their food laced with neurotoxins at doses that are known to leave individual bees susceptible to disease, dazed and confused isn’t helping them cope with their many other problems.

To return to the comments of Peter and Norman. Peter was being deliberately disingenuous. In referring to the Swedish study (Rundlof et al. 2015) as demonstrating that neonics do not harm honeybees he was relying on the audience being ignorant of the fact that there are many other types of bee, and that this very study showed devastating effects on bumblebees and solitary bees which he thought better than to mention [in case you don’t know, bumblebees are enormously important pollinators of crops and wildflowers, as are some wild solitary bees – in the UK, honeybees contribute no more than ~30% of crop pollination, the rest coming from wild insects].

Norman’s “it is complicated and confusing” is a cop-out. Science is complicated, that is why it takes years to train as a scientist, but it is our job to make sense of the evidence and summarise it in a useful and clear way. It is pretty clear to anyone even a little familiar with the scientific literature on wild bee declines and honeybee colony losses that these phenomena are due to multiple causes, including loss of flower-rich habitat, spread of parasites and diseases, and exposure to pesticides (Goulson et al. 2015). If we want to address bee declines we need to tackle all of these issues, and we need to do so with urgency, not stand around arguing about which is worse or saying we need to do more research before we take any action. 

Norman’s point that the neonicotinoid ban has forced farmers to use older, nastier chemicals that we know little about is interesting, and is an argument I have heard trotted out many times by the agrochemical industry. The neonic ban led UK farmers to increase spraying with pyrethroids in September (on young oilseed rape crops). These are older chemicals, but to say that we know little about them is nonsense. They have been in use for decades and are very well studied. If they were sprayed onto a crop at the time of flowering they would kill lots of bees. However, spraying them in September onto seedling oilseed rape is likely to have minimal impacts on bees; most wild bees are gone by then, and honeybees have no reason to be visiting the crop. Pyrethroids have very low persistence compared to neonics, so they will be not hang around until the spring when the crop flowers. Norman knows this well, since he spent most of his career working at Rothamsted, the very place that developed pyrethroid insecticides. Of course it would be better still if farmers investigated non-chemical means of managing their crop pests whenever possible, adopting an Integrated Pest Management approach, but that is for another day.

Despite what the agrochemistry industry and their supporters say, the evidence linking neonics to bee declines is overwhelming. But industry will continue to say that black is white, that neonics don’t harm bees, just as some continue to deny climate change because it suits their financial interests. As the American author Upton Sinclair once said, “It is difficult to get a man to understand something when his salary depends on him not understanding it”. We urgently need to put pressure on our politicians to ensure that they ignore this rubbish and take proper steps to prevent the wholesale pollution of our countryside with persistent neurotoxins. More broadly, we need to find ways to reduce the grip of the chemical manufacturers on the way we grow food. Like Brexit or not, it provides a golden opportunity, freeing British farming from the Common Agricultural Policy, and making it possible to steer it away from industrial, chemical farming towards more sustainable methods. If we do not, we will lose bees and much else of our wildlife for ever.    

 

References (links provided wherever possible)

Arce, AN et al. 2016. Combining realism with control: impact of controlled neonicotinoid exposure on bumblebees in a realistic field setting. Journal of Applied Ecology, October 2016 DOI: 10.1111/1365-2664.12792

Bonmatin J-M., Giorio C., Girolami V., Goulson D., Kreutzweiser D., Krupke C., Liess M., Long E., Marzaro M., Mitchell E., Noome D., Simon-Delso N., Tapparo A. 2015. Environmental fate and exposure; neonicotinoids and fipronil. ENVIRONMENTAL SCIENCE & POLLUTION RESEARCH 22: 35-67.

Botías, C., David, A., Horwood, J., Abdul-Sada, A., Nicholls, E., Hill, E., Goulson, D. 2015. Neonicotinoid residues in wildflowers, a potential route of chronic exposure for bees. ENVIRONMENTAL SCIENCE & TECHNOLOGY 49: 12731-12740.

Cutler GC, Scott-Dupree C (2007) Exposure to clothianidin seed-treated canola has no long-term impact on honey bees. J Econ Entomol 100: 765–772

David, A., Botías, C., Abdul-Sada, A., Nicholls, E., Rotheray, E.L., Hill, E.M. & Goulson, D. 2016. Widespread contamination of wildflower and bee-collected pollen with complex mixtures of neonicotinoids and fungicides commonly applied to crops. ENVIRONMENT INTERNATIONAL 88: 169-178.

Goulson D. 2015. Neonicotinoids impact bumblebee colony fitness in the field; a reanalysis of the UK’s Food & Environment Research Agency 2012 experiment. PEERJ 3:e854.

Goulson, D. 2013. An overview of the environmental risks posed by neonicotinoid insecticides. JOURNAL OF APPLIED ECOLOGY 50: 977-987.

Goulson, D., Nicholls E., Botías C., & Rotheray, E.L. 2015. Combined stress from parasites, pesticides and lack of flowers drives bee declines. SCIENCE 347: 1435-+.  

Pilling et al. 2013; A Four-Year Field Program Investigating Long-Term Effects of Repeated Exposure of Honey Bee Colonies to Flowering Crops Treated with Thiamethoxam. PLOSOne http://dx.doi.org/10.1371/journal.pone.0077193

Pisa L., Amaral-Rogers V., Belzunces L.P., Bonmatin J-M., Downs C., Goulson D., Kreutzweiser D.P., Krupke C., Liess M., McField M., Morrissey C.A., Noome D.A., Settele J., Simon-Delso N., Stark J.D., Van der Sluijs J.P., Van Dyck H. and Wiemers M. 2015. Effects of neonicotinoids and fipronil on non-target invertebrates. ENVIRONMENTAL SCIENCE & POLLUTION RESEARCH 22: 68-102.

Rundlof et al. 2015 Seed coating with a neonicotinoid insecticide negatively affects wild bees. Nature 521: 77-80

Straub, L. et al. Neonicotinoid insecticides can serve as inadvertent contraceptives. Proc. Roy. Soc. B doi : 10.1098/rspb.2016.0506

Whitehorn PR, O'Connor, S., Wackers, F. L. & Goulson, D. 2012. Neonicotinoid pesticide reduces bumble bee colony growth and queen production. Science, 336, 351-352

Woodcock, B.A. et al. 2016. Impacts of neonicotinoid use on long-term population changes in wild bees in England. Nature Communications 7, 12459.

  



[1] Norman Carreck asked me to add the following statement from himself:

"Norman Carreck has tried to remain objective throughout the debate about pesticides and bees. As he has stated publicly before, apart from his university undergraduate project in 1984 (a study looking at reducing fertiliser use on oilseed rape), which was funded by the then ICI Fertilisers Ltd, he has never worked on any project funded by any agrochemical company, nor has he ever received any private payment from any agrochemical company. He has also never worked on any project funded by any environmental campaigning organisation or pressure group, and has never received any private payment from any environmental campaigning organisation or pressure group".

[2] In the EU a moratorium was introduced in 2013 preventing the use of neonics on flowering crops such as oilseed rape. However, they remain very widely used on cereals and other crops, and total usage continues to rise year on year, according to Defra statistics (PUSSTATS website). As I have mentioned in previous blogs, yields of crops on which neonics can no longer be used have been as high or higher than usual since the moratorium. 

Are neonicotinoids killing birds?

Mar

07

Philip Lymbery, chief executive of Compassion in World Farming, has just launched his new book “Dead Zone: Where the Wild Things Were.” In it, he suggests that neonicotinoid insecticides may be contributing to bird declines. This claim has come under heavy fire from NFU and the agrochemical industry. In a recent online article NFU’s Dr Chris Hartfield is quoted as saying:

Evidence from real life field situations did not back up the claims, which are based on research by Dave Goulson, Professor of biology at Sussex University. Professor Goulson has published a paper which claimed a grey partridge would be killed by eating five treated seeds, and a sparrow after two. He also said birds which ate insects were ‘declining more rapidly in areas which use neonics’.

            “Dave Goulson’s theories about neonicotinoids poisoning birds are simply that – theories – and are not backed up by evidence from real life”, he added. In the UK, poisoning of all animals is investigated by the Wildlife Incident Investigation Scheme. If seed-eating farmland birds were being poisoned as a result of eating neonicotinoid treated seed, you would rightly expect this scheme to be finding these incidents. There are no incidents of bird poisoning resulting from the use of neonicotinoids over the last ten years. Promoting theories without the evidence to back them up is only going to damage the cause of pollinators and wildlife, and damage the public perception of science in general.

The paper to which Dr Hartfield refers was a review I published in 2013 in Journal of Applied Ecology (Goulson 2013).  In it, I say the following:

Although neonicotinoids do show relatively low toxicity to vertebrates, we might expect seed-eating vertebrates to be exposed to lethal doses if they consume treated seeds spilled during sowing. Typically, maize seeds are each treated with ~1 mg of active ingredient, beet seeds with 0.9 mg, and the much smaller oilseed rape seeds with 0.17mg (Rexrode et al. 2003; Anon 2012; Krupke et al. 2012). A grey partridge, typically weighing approximately 390g, therefore needs to eat ~5 maize seeds, 6 beet seeds or 32 oilseed rape seeds to receive an LD50. A grey partridge typically consumes ~25 g of seeds /day (Liukkonen-Anttila et al. 1999), equivalent to ~600 maize seeds, so clearly there is the potential for birds to swiftly consume a lethal dose. By a similar calculation, 3 maize seeds treated with imidacloprid would deliver more than the LD50 to a mouse. The US Environmental Protection Agency estimate that ~1% of drilled seeds remain accessible to granivorous vertebrates (i.e. they are not buried during drilling), and this does not include spillages which may occur, for example when transporting grain or loading hoppers. With typical sowing rates of ~50,000 seeds/ha for maize and 800,000 seeds/ha for oilseed rape, we might expect sufficient seed to be available on the soil surface to deliver an LD50 to 100 partridge or 167 mice for every hectare sown. 

            Lopez-Antia et al. (2013) fed imidacloprid-dressed wheat seed to red-legged partridge (Alectoris rufa) for 10 days and obtained 58% mortality, with the survivors exhibiting a range of sublethal effects.  This mortality rate, although considerable, is less than we might expect from the calculations above.  Lopez-Antia et al. report anecdotally that partridge did not avoid dressed seed when offered both dressed and undressed, but speculate that treated birds ate less than control birds, and so received a lower dose than expected. This requires further investigation, in this and other species, to determine how much treated seed vertebrates actually consume in the field. De Snoo et al. (1999) describe incidents of poisoning of wild partridge, pigeon and duck by seed dressed with imidacloprid reported by members of the public in France in 1994-5 (a time when neonicotinoid use was very low), but other evidence for effects in the field is lacking and it is unclear whether public reporting is an efficient means of detecting such incidents.

Since 2013, there have been a number of other scientific publications linking neonicotinoids to declines of birds and other vertebrates, most of which are reviewed here. I would draw your attention to two in particular. Firstly, in a high profile paper in the journal Nature, Hallmann et al. (2014) demonstrate that geographic patterns of declines of insect-eating birds in the Netherlands are explained by local levels of environmental pollution with the neonicotinoid imidacloprid.  They conclude that this is unlikely to be due to direct toxicity, but that it is probably simply that in areas where insecticide use is high there are few insects for the birds to eat. Seems pretty plausible to me.

Secondly, a recent study of bird poisoning incidents in France shows that, between 1995 and 2014, there were 101 incidents involving 734 dead animals in which toxicological reports detected imidacloprid, and where the death is likely to be associated with agricultural use of seed treatments. 70% of these incidents happened during autumn cereal sowing. Grey partridges and various pigeon species were the ones most frequently killed.

According to Dr Hartfield, there have been no such incidents in the UK. This strikes me as very odd. Farming in France is very similar to the UK; most of the same crops are grown, and pesticide uses are very similar. I rang the UK Wildlife Incident Investigation Scheme to ask them whether they actually test dead birds for neonicotinoids. The person I spoke to did not know, and asked me to send in an email request, which I have done. When I get a reply, I’ll update the blog.

So, Dr Hartfield, my theories are more than “just theories”. “Real life” evidence from the Netherlands and France strongly supports them. The absence of direct evidence from the UK should not be interpreted as evidence of absence – if you don’t look for something, you won’t find it.   

The ongoing complacency of NFU, and their willingness to aggressively attack scientists who speak out against overuse of pesticides does them no credit. Farming bird populations are collapsing, along with most other farmland wildlife. Isn’t it time the NFU faced up to this, and took some responsibility?

 

Farmland bird population change (from JNCC)

 

References

Goulson, D. 2013. An overview of the environmental risks posed by neonicotinoid insecticides. JOURNAL OF APPLIED ECOLOGY 50: 977-987.

 

Pesticides in “Bee-Friendly” flowers

Jun

01

Take a walk around your local garden centre and you will see a mouth-watering display of gorgeous plants on display. You might note that some are specifically labelled as bee or pollinator friendly, with a picture of a cartoon bumblebee on the label. The Royal Horticultural Society (RHS) provide a “Perfect for Pollinators” logo which can be added to the label of any of the long list of garden plants that they judge to be good for pollinators. If you like hearing the buzz of bees in your garden, and want to do your bit to help our wildlife, you might well be tempted. Indeed, I have often spent a small fortune myself on potted plants when I only went to the garden centre to buy a pack of vegetable seeds. The big DIY and supermarket chains are similar – somewhere by the main entrance you will see a range of colourful plants in plastic pots and trays, some of them labelled as bee-friendly.

            If, like me, you’ve ever succumbed to the temptation to buy these plants, you may be somewhat concerned by the results of our latest research. Here at Sussex University we have been busy screening the leaves, pollen and nectar of these plants to see if they contain pesticides. We bought flowering plants from a range of major outlets; Wyevale (the biggest garden centre chain in the UK) and also Aldi, B&Q and Homebase. We deliberately bought plants that are known to be attractive to bees and butterflies; most of them had a bee-friendly logo, often the RHS one.

We found that most of these plants contained a cocktail of pesticides, usually a mixture of fungicides and insecticides. I wish I could say that I was surprised by the results, but sadly I wasn’t, for this mirrors similar studies performed in other countries. Only two out of 29 plants contained no pesticides. Seventy six percent of them (22/29) contained at least one insecticide, and 38% contained two or more insecticides. One flowering heather plant contained five different insecticides and five different fungicides – a veritable toxic bouquet. Seventy percent of the plants contained neonicotinoids (insecticides that are notorious for their harmful effects on bees), commonly including the ones banned for use on flowering crops by the EU (for the technically minded, 38% contained imidacloprid, 14% contained thiamethoxam and one contained clothianidin). Enough detail; you get the picture. Plants sold as ‘bee-friendly’ plants are usually stuffed full of pesticides.

Just before our results went public, B&Q (who knew that out study was appearing imminently) announced that they were prohibiting their suppliers from using neonicotinoids on their plants from February 2018. This is of course a great step forwards; well done B&Q, next time I need some screws or shelving I will be heading your way, and I hope others do likewise. Once our results were out Aldi declared that they stopped using neonicotinoids in October 2016 (we bought the plants we tested from them in July 2016). Also great news.  

Homebase and Wyevale have so far declined to make any public comment, despite high profile articles about the work in the Daily Mail and Independent. The Horticultural Trades Association, which represents the gardening industry, has been less than positive (http://bit.ly/2rXM4sL). Firstly, they claim that the three neonicotinoids banned by the EU on flowering crops are not used in horticulture (which would seem to simply be untrue). They then go on to say the “industry works closely with government bodies and other stakeholders to uphold high standards of environmental management”. They say that the concentrations of pesticides we found are at “low levels”, that we only sampled from “a very restricted area of the country”, and they suggest that the presence of clothianidin in one plant shows that our samples were contaminated, since this product has never been approved for use on ornamentals. In other words, instead of engaging positively, they try to undermine and play down our work.

Let’s have a closer look at their criticisms. Firstly, the concentration of the pesticide is of course important. Modern analytical techniques are very sensitive and tiny concentrations can be detected. Perhaps the concentrations we detected are all too low to do any actual harm? For neonicotinoids, the concentrations typically found in the nectar and pollen of treated crops such as oilseed rape are in the range 1-10 parts per billion (ppb). Exposure to such concentrations has been found to impair bee navigation and learning, reduce egg laying, lower sperm viability, and suppress the immune system. In a study with bumblebee nests we found that giving them pollen with 6ppb of neonicotinoid reduced nest growth and resulted in an 85% drop in the number of new queens produced[1]. In the ornamental flowers, we found imidacloprid at up to a maximum concentration of 29ppb, clothianidin at 13ppb and thiamethoxam at 119ppb. In other words, concentrations far higher than those known to harm bees. The claim that we only sampled from a “very restricted area” is pretty absurd. It is true, we sampled from stores near Brighton, but these are huge chains with a national/international supply network. Are HTA really suggesting the problem is peculiar to East Sussex? On the presence of clothianidin and the suggestion that our samples were contaminated, HTA need to learn a bit more about pesticides. As well as being used as a pesticide in its own right, clothianidin is a breakdown product of the closely related chemical thiamethoxam. The Ageratum plant containing the clothianidin also contained much higher levels of thiamethoxam, presumably the product with which it had been treated. So, not evidence of contamination at all.          

            I would argue that, by quibbling over details and focussing on neonicotinoids, HTA are missing the bigger picture, as indeed are B&Q and Aldi. Neonicotinoids are undoubtedly bad for bees, but what about all the other chemicals? If I buy a plant to feed to bees I don’t want it to have been drenched with a pyrethroid or organophosphate insecticide either. Both are highly poisonous to bees (and organophosphates are exceedingly toxic to people too). Even some of the fungicides have been found to harm bees[2]. If I’m buying plants to encourage wildlife, I don’t want the lingering worry that I might be accidentally poisoning my bees, hoverflies and butterflies. I don’t use any pesticides in my garden – I simply don’t need them. I don’t want to bring them in accidentally.   

            It is a shame that the horticulture industry seems largely unwilling to engage over this issue. It is perhaps not surprising, since their track record is not great. They’ve been continuing to promote and use peat-based composts for many decades despite the ready availability of perfectly good alternatives (in case you didn’t know, peat extraction does terrible damage to peat bogs, exacerbates flooding and ultimately releases huge amounts of carbon dioxide into the atmosphere). With birds, bees and butterflies all in rapid decline (2016 was the worst year ever for British butterflies), we all need to be willing to admit our mistakes and change our ways. HTA and the big garden chains such as Wyevale could really help to make a difference if they wanted to. I’d be very happy to help if they would like some advice (Wyevale, how about launching a new organic range of genuinely bee-friendly plants?)

Until the gardening industry gets its act together, I’d suggest the following. If you must buy plants, buy from an organic nursery, or failing that from B&Q or Aldi. Better still grow them from seeds, or if you haven’t the patience, plant swap with your friends and neighbours (if anyone wants some comfrey roots and lives near E Sussex I’d be happy to give you some, pesticide free, it is a fabulous plant for bees). We really can make our gardens into havens for wildlife, but not by driving to the garden centre to buy pesticide-laced plants grown in peat-based compost inside disposable plastic pots.    

 -----------------------------

Our research describing in detail the pesticides we found is here: http://www.sciencedirect.com/science/article/pii/S0269749117305158 

It was published in the journal Environmental Pollution, May 2017. 



[1] Whitehorn et al. 2012, Science, 336: 351-352.

[2] Bernauer et al. 2015, Insects 6: 478-488