David's blog posts

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.

 

Launch of the Worldwide Integrated Assessment (WIA) on the environmental impacts of systemic pesticides

Jun

27

On Tuesday this week I was in Brussels, for a press conference to launch a major series of scientific publications on the impacts of neonicotinoid insecticides on the environment. On the same day, press conferences were also held in Manila, Tokyo and Ottawa. The publications are the culmination of 5 years work involving more than 50 scientists from 4 continents, and together we reviewed evidence from >800 scientific papers. Our findings are being published as 7 papers in a special issue of the journal Environmental Science and Pollution Research. All have been accepted for publication following full, independent, scientific peer-review. The first of the seven is online now at http://link.springer.com/article/10.1007/s11356-014-3180-5; this deals with impacts on vertebrates. The rest of the papers will appear soon as the journal finishes processing them for publication.

The conclusions of our work, in brief, are that these systemic pesticides are accumulating in soils and polluting waterways and natural vegetation across the world, leading to widespread impacts on wildlife inhabiting farmland and aquatic habitats. There is also growing evidence that much of their use is unnecessary and ineffective. But you can read all about this over the coming months as the papers come out: all of them are to be open access.

On Monday, the day before the press conference and before anyone could have seen the full set of documents, I received a rebuttal of our work from Croplife, an organisation that represents the agrochemical industry. It was quite clear that they hadn’t read any of it. Their criticisms were: that the work was selective in what it reviewed (we looked at 800 papers, everything that we could find); that we looked only at lab studies (a bizarre claim, and completely untrue); that we ignored the economic importance of neonicotinoids and didn’t consider how farmers would cope without them (there is a whole paper in the WIA just on this topic).

We have also been criticised because not all of our papers are yet available. Had this been a single report, just placed on the internet without scientific review, we could easily have made it all available. This is what industry usually does. But the scientific review and editing process is slow and not all of the papers were quite ready. On the plus side, they have the huge advantage that they have all passed independent scrutiny.  

On Wednesday, Syngenta launched a request to the UK government for an exemption to the European moratorium. They want to treat 186,000 hectares of oilseed rape woth a neonicotinoid – 30% of the UK crop – because they say that otherwise there is a “danger to production”. There appears to be no scientific evidence to back up this claim. Indeed, just a week ago on 18 June an industry spokesman appeared before the UK’s Environmental Audit Committee and was asked to provide a single scientific study showing that neonicotinoid seed dressings increased yield of any arable crop. Embarrassingly, he could not. They’ve been selling neonics for 20 years, but can provide no evidence that they work!? How do they differ from the quack doctors of days gone by, who peddled cure-alls on street corners with their slick patter?

One can read Syngenta’s request another way – they seem to be conceding that 70% of the UK’s oilseed rape doesn’t need treating with neonics. Why then was 100% treated before the moratorium?

This simply appears to be a ploy by industry to bypass the EU moratorium, which was based on sound scientific evidence, and recommended by the European Food Standards Agency. If you’d like to sign a petition against their request, go to: https://secure.38degrees.org.uk/a-ban-is-a-ban

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]

Does anyone remember Rachel Carson? More on pesticides and bees...

Jan

15

As part of a project to study impacts of pesticides on bumblebees, we have recently been surveying what chemicals the local farmers in East Sussex use each year. Perhaps I was naive, but I found the figures to be astonishing. Below, I’ve pasted a list of the chemicals applied to two fairly typical fields, one with winter oilseed rape, one with winter wheat, in a single growing season (2012/13). For both crops, it is a very long list.

I should stress that these are perfectly normal farms; not especially intensive, situated on the edge of the South Downs, an area of gentle hills, hedgerows and wooded valleys. Beautiful, rural England; Constable would have liked it here. But let’s look at it from a bee’s perspective, focussing on the oilseed rape, since this is a crop they will feed on when it flowers:

Firstly, the crop is sown in late summer with a seed dressing containing the insecticide thiamethoxam. This is a systemic neonicotinoid, with exceedingly high toxicity to bees. We know it is taken up by the plant, and that detectable levels will be in the nectar and pollen gathered by bees in the following spring. In November, despite the supposed protection of the neonicotinoid, the crop is sprayed with another insecticide, the charmingly named Gandalf. What harm could the wise old wizard possibly do? Gandalf contains beta-cyfluthrin, a pyrethroid. Pyrethroids are highly toxic to bees and other insects, but there should be no bees about in November so that is probably OK. The following May, when it is flowering, the crop is sprayed with another pyrethroid,  alpha-cypermethrin. Less than three weeks later, the crop is blitzed with three more pyrethroids, all mixed together, a real belt-and-braces approach. Why use one when three will do? The crop is still flowering at this point (it was a late year), and would be covered in foraging bumblebees and other pollinators.

In between, the crop is also treated with a barrage of herbicides, fungicides, molluscicides and fertilizers – 22 different chemicals in total. Most of these may have little toxicity to bees in themselves, but some, such as a group of fungicides (the DMI fungicides), are known to act synergistically with both neonicotinoids and pyrethroids, making the insecticides much more toxic to bees. On the final application date, when the crop is flowering, one of these fungicides (prothioconazole) is added to the tank mix with the three pyrethroids. Any bee feeding will be simultaneously exposed to the three pyrethroids, the thiamethoxam in the nectar and pollen, and a fungicide that makes these insecticides more toxic.     

We don’t know what impact all of this really has on them. The safety tests generally expose test insects to just one chemical at a time, usually for just 2 days, but in reality they are chronically exposed to multiple pesticides throughout their lives. The fact that we still have bees in farmland suggests that they must be pretty tough. More broadly, we don’t know what impacts all of this has on other pollinators, or wildlife in general. Industry would tell us that all is well. They would also tell us (and the farmers that they advise) that all of these applications are vitally important parts of crop production, and that without them food production would collapse. I have my doubts. Is this really how we want to see the countryside managed? Do we really want to eat food produced this way?

I think I might head home early and finish digging over my veggie plot. At least I can control what goes into that.  

[PS If you find this blog of interest, please share it with your friends using the buttons below right] 

Winter Oilseed Rape

Date

Type of compound

Brand name

Active ingredients

Application method

25/08/2012

 

Insecticide and fungicide

Cruiser

280 g/l thiamethoxam, 8 g/l fludioxonil and 32.3 g/l metalaxyl-M

Seed dressing

Herbicide

Shadow

Quinmerac, Dimethenamid-p, Metazachlor

Spray

Herbicide

Dictate

480g/litre bentazone as sodium salt in the form of soluble concentrate

Spray

Fungicide

Fiddle

Clomazone

Spray

08/09/2012

Molluscicide

Tds Major

Metaldehyde

Slug pelleter

12/09/2012

Herbicide

Shadow

Quinmerac, Dimethenamid-p, Metazachlor

Spray

10/10/2012

Fungicide

Crawler

Carbetamide

Slug pelleter

05/11/2012

Fungicide

Genie 25

Flusilazole

Spray

Insecticide

Gandalf

Beta-cyfluthrin

Spray

16/02/2013

Fertiliser

Double Top

Ammonium Sulphate and Ammonium Nitrate

Fertiliser spreader

Fungicide

Crawler

Carbetamide

Slug pelleter

Herbicide

Pilot Ultra

Quizalofop-P-ethyl

Spray

10/04/2013

Fertiliser

Nitram

Ammonium nitrate

Fertiliser spreader

22/04/2013

Fertiliser

Nitram

Ammonium nitrate

Fertiliser spreader

17/05/2013

Fungicide

Filan

Boscalid

Spray

Fungicide

Flanker

Picoxystrobin

Spray

Insecticide

Alert

Alpha-cypermethrin

Spray

05/06/2013

Fungicide

Propulse

Fluopyram, Prothioconazole

Spray

Insecticide

Hallmark Zeon

100 g/l lambda-cyhalothrin and 1,2-benzisothiazolin-3-one

Spray

Insecticide

Gandalf

Beta-cyfluthrin

Spray

Insecticide

Mavrik

Tau-fluvalinate

Spray

  

Winter wheat

20/09/2012

Insecticide and fungicide

Redigo Deter

50 g/L (4.3% w/w) prothioconazole and 250 g/L (21.4% w/w) clothianidin

Seed treatment

28/09/2012

Molluscicide

Tds Major

Metaldehyde

Slug pelleter

26/10/2012

Molluscicide

Osarex W

Metaldehyde

Slug pelleter

02/11/2012

Molluscicide

Tds Major

Metaldehyde

Slug pelleter

06/11/2012

Herbicide

Dictate

480g/litre bentazone as sodium salt in the form of soluble concentrate

Spray

Herbicide

Fidox

Prosulfocarb

Spray

Herbicide

Liberator

Flufenacet, Diflufenican

Spray

Insecticide

Gandalf

Beta-cyfluthrin

Spray

10/01/2013

Molluscicide

Tds Major

Metaldehyde

Slug pelleter

06/03/2013

Fertiliser

Sulphur Gold

Amonium sulphate-nitrate

Fertiliser spreader

08/04/2013

Fertiliser

Nitram

Amonium nitrate

Fertiliser spreader

23/04/2013

Herbicide

Quintacel5c

645 g/l (57% w/w) chlormequat chloride

Spray

Herbicide

Scitec

Trinexapac-ethyl

Spray

Fertiliser

Bittersaltz

Magnesium Sulfate

Spray

Fertiliser

Nutriphite Excel

Phosphate

Spray

30/04/2013

Fertiliser

Nitram

Amonium nitrate

Fertiliser spreader

07/05/2013

Fungicide

Bassoon

Epoxiconazole

Spray

Fungicide

Kingdom

Boscalid, Epoxiconazole

Spray

Fungicide

Bravo 500

Chlorothalonil

Spray

Herbicide

Quintacel5c

645 g/l (57% w/w) chlormequat chloride

Spray

Herbicide

Oxytril Cm

Ioxynil, Bromoxynil

Spray

27/05/2013

Fungicide

Adexar

Epoxiconazole, Fluxapyroxad

Spray

Fungicide

Bassoon

Epoxiconazole

Spray

Fungicide

Bravo 500

Chlorothalonil

Spray

19/06/2013

Fungicide

Cello

Prothioconazole, Spiroxamine, Tebuconazole

Spray

Note: These data were compiled from information provided by the farmer, by my wonderful postdoc Dr Cristina Botias-Talamantes. Keep an eye on this blog for more revelations from her ongoing work.

Dave Goulson's research lab website

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

  

One more unto the breach; a look at Defra’s stance on neonicotinoids

Sep

13

On 27 March 2013, Defra released “An assessment of key evidence about neonicotinoids and bees”. They recently reiterated their conclusion that the ban was 'unnecessary and unjustified'. Defra’s chief scientist, Prof Ian Boyd, can be viewed on YouTube expounding the points made in their March document. I’d like to draw your attention to something which strikes me as very odd.

The report flags up three key studies that suggest there may be a strong link between exposure to neonicotinoids and bee ill-health. They then say that five field studies provide contradictory evidence, suggesting little or no impact of these pesticides on bees in the real world. The remainder of the document is a detailed critique of the three studies that did find a link – suggesting that they gave the bees unrealistic doses of pesticide, and that they were “lab” studies and so not representative of the real world (neither of which is true – all of the studies were performed largely or entirely outside, with free-flying bees - but that is for another day).

What I find extremely odd is that the five field studies are not subject to the same examination. Why on Earth not? If we are to weigh up the evidence, surely we should examine each study equally carefully? They are not mentioned again, although the document ultimately concludes that they were correct in their findings.

Let me fill in the gap, and provide a brief evaluation of these five documents, held up by Defra as “field studies in which bees were allowed to forage naturally in the presence of crops treated with neonicotinoids”:

1)      Blacquiere et al., (2012), Ecotoxicology 21: 973-992. There is no field study in this paper. It is a broad review of the subject, but presents no new data at all.

2)      Chauzat et al., (2009), Environmental Entomology 38: 514-523. This study examines mortality in 125 honeybee hives in France over three years, in relation to levels of pesticides found in their pollen, honey, and in the bees themselves. Low levels of imidacloprid were detected in the hives, but hive mortality was low, and imidacloprid exposure did not predict mortality. However, no experiment was conducted. There were no control nests, and we do not know if any nests were near treated crops. This study appears to be perfectly valid as far as it goes, but is not a good test of whether neonicotinoid pesticides harm bees.    

3)      Hecht-Rost S (2009) Eurofins-GAB GmBH. This is an industry report, presumably funded by an agrochemical company. It is not published in a scientific journal, and hence has not been subject to peer review. I cannot obtain a copy, so it is impossible to evaluate.

4)      Thompson H et al. (2013). This is also unpublished, and so has not been subject to peer review. It is a study conducted by Fera (the research wing of Defra) in which bumblebee colonies were placed next to an untreated, control field of oilseed rape, or next to fields treated with either imidacloprid or clothianidin. It is unreplicated – there was only one control field – and the nests by the control field were all exposed to neonicotiniods, so there were no longer any controls. In short, it was a disaster.

5)      Genersch E et al. (2010). Apidologie 41: 332-352. At a quick glance, this one looks quite good – similar to no. 2, but on a bigger scale. There is no controlled experiment, but they followed the fates of over 4,000 honeybee hives over time. They conclude that Varroa and other parasites are important in causing honeybee ill-health, but not pesticides. However, if you look a little deeper this is somewhat misleading. Only 210 of the colonies were actually screened for pesticides, while all were screened for Varroa. In their analysis of the impacts of pesticides, the authors sum exposure to all pesticides (including fungicides and herbicides), and then use this value to try to predict winter colony loss. This is a very odd analysis to do, since herbicides and fungicides mostly have very low toxicity to insects. Not surprisingly, they find no relationship between total pesticide exposure and colony death. They don’t actually perform ANY analysis of the impacts of the insecticides alone, or of neonicotinoids in particular. The study appears to have been funded by the agrochemical industry.

In summary, these five studies tell us almost nothing about the impacts of neonicotinoids on bees. There is not one successful experiment, with replication and proper controls, to be found amongst them. Two of the five aren’t actually published studies at all.

Compare this to the three key studies that Defra are at pains to dismiss. They are published in the best journals in the world (two in Science and one in Nature). They will have been through an excruciatingly tough peer review process. All three have good levels of replication, and proper controls. Which group of studies would you trust?

Have Defra actually read the five studies in which they place their faith? I'm not convinced that they have.

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?

 

 

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

 

  

 

Bumblebees on Springwatch

Jun

03

Ah, the perils of live TV. They say never work with animals or children, so I fear I am in trouble. Tomorrow I am appearing live on "Springwatch in the Afternoon", broadcast from deepest, darkest Wales (an RSPB reserve somewhere near Aberystwyth). I'll be ineptly trying to plug my new book, A Sting in the Tale, while catching and handling bumblebees, talking about bumblebees, building a nest site for bumblebees, and being rude about garden centre bedding plants (which are rubbish for bees - intensive breeding has left them without nectar or pollen, or so bizarrely deformed that insects can't fit into them any more). What could possibly go wrong? 3pm, tuesday 4th April. Enjoy :)

Dave Goulson's research lab website

Neonicotinoids and bees; what is the fuss all about?

May

07

When I was first asked to support a ban on neonicotinoid insecticides, I was very sceptical. I’d previously been asked to sign up for campaigns claiming that bee declines were due to mobile phones, GM crops, overhead power lines, and various other eccentric or implausible notions. However, a review of the science suggested that there was something worth investigating, and for the last two years I seem to have had time for little else.

The issue has focussed largely on harm these chemicals might be doing to bees, both domestic honeybees and wild pollinators such as bumblebees. I’ll focus on bumblebees here, for they are the subject of my particular expertise. Neonics are widely applied as a seed dressing to crops such as oilseed rape, and being systemic they spread through the plant tissues into the nectar and pollen. They are highly toxic to insects; for example the “LD50” (the dose that kills half of test subjects) in honeybees is about 4 billionths of a gram. To put that in context, 1 gram – little more than the weight of a sachet of salt – would provide an LD50 to 250 million honeybees, or roughly 50 metric tonnes of bee. They are neurotoxins, binding to neural receptors in the brain and causing swift paralysis and death.

Until recently, there had been few studies of neonics and bumblebees, all small scale and nearly all performed in cages or glasshouses. Taken together, they seemed to suggest that exposure to very low levels of these chemicals, such as might occur when a bee fed on a treated oilseed rape crop, was not sufficient to kill many bees, but it seemed to affect their behaviour, particularly their ability to learn, gather food, and navigate. These are not impacts that are assessed by any of the safety tests by which pesticides are judged (although there are plans to introduce such tests in Europe in the very near future). They are also impacts that are likely to be much more important in the field, when bees naturally perform astonishing feats of navigation and learning when gathering food from flowers. It seemed to me, and to a number of other researchers around the world, that there was a need to study what impacts these sublethal affects might have on bee colonies in natural situations.

To investigate this, we exposed bumblebee nests to the concentrations of neonics found in the pollen and nectar of oilseed rape for two weeks, and then placed the nests out in the field to see how they fared compared to control nests. Over the following 6 weeks the treated nests grew more slowly, and ultimately produced 85% fewer new queens. Since our study, work from other labs has confirmed that field-realistic doses greatly reduce pollen collection in bumblebee workers, potentially explaining why our treated nests performed poorly. It has also been found that concentrations of neonicotinoid as low as 1 part per billion (ppb) in their food cause a drop in egg laying in bumblebees of 30%. Considerably higher concentrations than this have been found in pollen of treated crops (the typical range in pollen is about 1-10 ppb, although 50 ppb has been found in lucerne pollen, and over 100 ppb in melon pollen).

For bumblebees, the evidence so far is convincing and coherent; exposure to levels of neonic commonly found in crops have profound impacts on colony success. The only study which apparently contradicts this was recently placed online by Defra, a report describing a study they conducted in 2012 in which they attempted to repeat our work but with the pesticide exposure phase of the experiment occurring in the field. They placed bumblebee nests next to the only untreated field of oilseed rape they could find, or next to one of two other fields treated with two different neonics, and they followed the colonies over time. Unfortunately they had no replication – just one field per treatment – and, disastrously but interestingly, the control nests all became contaminated with neonics. The summary of this report claims the study shows no clear effect of neonicotinoids on bumblebee colonies; hardly surprising, given the absence of any controls – and hardly the sort of convincing evidence one would wish government to base its policies upon. It is also not really true – in fact there was a highly significant negative relationship between neonicotinoid levels recorded in each nest and how well the nest performed, but the authors removed this relationship by “taking out outliers” – by which they mean removing the nests that received the highest exposure (which also happened to be the nests that performed most poorly) from their data set and then re-ran the tests.

Perhaps the most valuable lesson to be learned from this work is that bumblebee nests placed into the English landscape become contaminated with multiple types of neonic, even when on farms where none are used. Many of the nests had concentration of neonic higher than 1 part per billion, and most had detectable levels of at least two different neonics.  Bizarrely, the results suggest that bumblebees have a particular predilection for the neonic thiamethoxam, for the control bees seemed to have ignored the untreated rape field right next to their nests and flown a long way to find a thiamethoxam-treated crop.

While the debate has focussed heavily on bees so far, there are broader issues to consider. Neonics are very persistent in soils, and evidence has recently emerged that they accumulate over time; a study in East Anglia performed by Bayer in the 1990s found concentrations up to 60 parts per billion in soil after 6 years of annual use. This is likely to be enough to have profound impacts on soil life. It has also emerged that they get into field margin vegetation, and into streams and ponds. A concentration of just 0.6 parts per billion is enough to kill mayfly nymphs. It may be that, while focussing on bees, we have missed the bigger picture. 

 

The economics

A common argument in favour of neonics is that they provide huge economic benefits, and that the alternatives are worse. A glossy document produced by the “Humbolt Form” (funded exclusively by the agrochemical industry) in early 2013 claimed that a ban on neonicotinoids would cost the EU 17 billion Euros and 50,000 jobs. However, the hard evidence for these claims seemed to be lacking. Indeed, the evidence that neonicotinoids are important for crop production is surprisingly difficult to find. Studies from USA show that yields of soya bean do not benefit at all from neonic seed dressing, despite their application being standard practice. Sadly, similar experiments in the UK have not been conducted. Since farmers get most of their agronomic advice from companies that supply pesticides, it is reasonable to suppose that a good proportion of UK pesticide use may be unnecessary.

 

Whatever happened to IPM?

When I was at University in the 1980’s, I read Rachel Carson’s Silent Spring, and was taught about the terrible mistakes made in agriculture in the 1950s and 1960s when indiscriminate use of persistent, broad-spectrum insecticides, and an abandonment of traditional cropping practices such as rotations led to huge pest outbreaks. The pest insects had all become resistant, while their natural enemies had largely been eradicated. As a result, an approach called Integrated Pest Management (IPM) had been developed, and we were taught that this was the future of pest control. IPM is predicated on minimising pesticide use: farmers monitor their crop pests, and only take action when necessary; they encourage natural enemies as far as possible, use crop rotations and other cultural controls to suppress pests, and only use the insecticides as a last resort. Even then, they avoid those that persist in the environment.

Whatever happened to this philosophy? Why are we now applying pesticides prophylactically to more or less all crops? Did we learn nothing from our past mistakes?  

 

The politics

The EFSA spent 6 months evaluating all the evidence, and concluded that current use of neonics poses unacceptable risks to bees. The UK’s Environmental Audit Committee (a group of MPs) agreed. Numerous NGO’s, including the RSPB, who are normally very cautious, also agree. Even the WI support a ban. What was once a radical stance is now where the vast majority of informed opinion lies; on 29 April the EU member states voted for a 2 year moratorium on use of the three most-commonly used neonics on crops visited by bees.

The UK voted against the ban, with Chief Scientific Advisor Sir Mark Walport saying that everyone else had misinterpreted the evidence. He also argued that applying the precautionary principle would lead us to continue using neonicotinoids, an argument that few of us could follow.

 

What Next?

The moratorium is only for two years, yet we have clear evidence that it will take far longer than this for neonicotinoids that have accumulated in soils to break down. In any case, they are still being widely used, on winter wheat for example, and some types of neonic are not included in the ban.  So it is unlikely that we will see the benefits of the moratorium in rebounding bee populations any time soon. In any case, there seems to be no plan to actually monitor bee populations, so even if they did recover it is not clear how we would know.

What will farmers do without neonics? It is hard to say. It would be nice if they returned to an IPM approach, but with their main / only source of advice being from people with a vested interest in selling chemicals, this seems unlikely. 

 

Have we solved the bees’ problems?

I’m afraid the answer is an emphatic NO. Bees have been declining for many decades, and much of their decline has been due to loss of flower-rich habitat, which has been exacerbated by the arrival of non-native diseases, and by widespread use of pesticides. We have taken a step to reduce (but not remove) their exposure to some brands of one type of pesticide, for two years. That is nowhere near enough. If we want to ensure healthy populations of honeybees, bumblebees, and other wild pollinating insects upon which we depend for our crop production, and more generally if we wish to support the healthy, diverse ecosystems upon which our future health and wellbeing depends, then we need to find ways to produce food in a sustainable way which incorporates the needs of biodiversity. At present we are failing to do this.

 

Dave Goulson's research lab website