Evidence of pesticide harm to bees is now overwhelming

Evidence of pesticide harm to bees is now overwhelming

Yet more top-quality research shows current regulation is woefully inadequate in protecting the creatures that pollinate much of our food


A UK government review of the evidence linking pesticides and harm to bees concluded it did not justify changing existing regulation. Photograph: Julian Stratenschulte/EPA
Here we go again. Yet more research has been published in the world's most prestigious, peer-reviewed journals showing that extremely widely-used pesticides have very damaging effects on bees, yet the only response from the government is inaction.

The new paper, published in Nature, shows that bumblebees foraging naturally and exposed to realistic doses of pesticides suffer in two key ways. First they are about twice as likely to die: two-thirds of the bees are lost when exposed to two pesticides compared to only a third when not exposed. Second, the exposed bees are half as successful in gathering food.

The new results reveal, again, shameful failings in the regulatory regime. The ecotoxicology tests currently required only look at honey bees. Yet bumblebees, the subject of the new research, are just as important in providing the pollination that creates much of the food we eat. Tomatoes, for example, rely on bumblebees. Furthermore, bumblebees are very different, bigger in size individually, but living in colonies of just dozens, compared to the tens of thousands in honey bee colonies.

Another failing is that current tests require just 96 hours of exposure, but the new research only saw the damaging effect after three weeks. "If we had done our study for just 96 hours, our conclusions would have been very different," says Nigel Raine, at Royal Holloway, University of London, one of the research team.

Yet another failing is that pesticides are only tested individually, not in the combination bees are exposed to in reality. The new work clearly shows a damaging cumulative effect from a combination of just two pesticides.

The reaction from pesticide manufacturers is the same as ever: the experiments are "unrealistic". Raine rejects this: "It is hard to see what you could do better." I think he has a point. The only truly "realistic" experiment would have no intervention at all, meaning you could collect no data. The manufacturers are making the perfect the enemy of the good. They also claim their own data shows there are no harmful effects, yet have not published it.

The manufacturers do have some scientists supporting their view that there is too little evidence of harm to act. James Cresswell, an ecotoxicologist at the University of Exeter, said:" It certainly wouldn't be fair to say that this research spells doom for wild bees."

Creswell also criticised research published the journal Science in March, which showed that honeybees consuming one pesticide suffered an 85% loss in the number of queens their nests produced. Subsequently, Creswell was granted £136,000 by pesticide manufacturer Syngenta to fund a research post. Cresswell said there was no connection between the two. "I consider myself an impartial scientist," he told me, adding he had not spoken to Syngenta until after his criticism was sent to Science.

The UK government has already reviewed some of the evidence of the serious harm pesticides cause to bees but, unlike other countries, chose to do nothing. But parliament is now investigating the issue, with the call for evidence open until 2 November.

"Ministers may want to start doing their homework on pesticide policy and biodiversity, because we will be calling them before parliament to answer questions," said Joan Walley MP, chair of the Environmental Audit Committee, when announcing the enquiry. "In particular, we will be scrutinising the evidence behind the government's decision not to revise pesticide regulations or follow other European countries in temporarily suspending the use of insecticides linked to bee decline."

The questions are mounting: this latest research shows the need for answers is becoming ever more urgent.

The silence of the bees: government refuses to act on pesticide evidence

The silence of the bees: government refuses to act on pesticide evidence

Extrapolating scientific data appears to be fine if policy-makers like where it leads - such as a badger cull - but is abhorrent if they don't, as with bees

A honey bee joins a meadow brown butterfly on a buddleia flower. Photograph: Jenifer Bunnett/Alamy
Here's an illustrative tale of how science is used and abused in government policy making. In some circumstances, as with the imminent badger cull, you can take scientific evidence and extrapolate it to breaking point in order to justify the decision you have already taken.

Today, on the issue of bees and pesticides, we see the opposite. Despite serious evidence of great harm being caused to bees by sub-lethal doses of neonicitinoid pesticides - published in the world's most prestigious journals - the government has decided that no changes to regulation whatsoever are required, because the case has not been proven beyond all doubt.

So extrapolation is fine if you like where it takes you, but abhorrent if you don't. Evidence-based policy making remains as dreamy a concept as ever, it seems, even with something as critical as keeping the nation's pollinators in good health and our food supply secure.

The bee fiasco began in March with the publication of two studies in Science. The first found that bees consuming one pesticide suffered an 85% loss in the number of queens their nests produced, while the second showed a doubling in "disappeared" bees, those that failed to return from food foraging trips. The work was the first to be carried out in realistic, open-air conditions and used levels of neonicotinoids found in fields.

Professor Mickaël Henry, at INRA in Avignon, France, who led the "disappeared" bees study was under no illusion about the implications of his findings: "Under the effects we saw from the pesticides, the population size would decline disastrously, and make them even more sensitive to parasites or a lack of food." He said current regulation was inadequate.

These high profile studies - and others - prompted the UK's environment ministry (Defra) to investigate. "It is appropriate to update the process for assessing the risks of pesticides to bees in the light of scientific developments – including the latest research," it stated.

Now, six months on, it has delivered its verdict: "The recent studies do not justify changing existing regulation." How can this be? Defra states:

The studies were interesting but they either used neonicotinoids at a higher level than is currently permitted, or the studies weren't carried out under field conditions. The studies did not show that currently permitted uses of neonicotinoids have serious implications for the health of bee populations.

The authors of the studies dispute the suggestion that both the doses and conditions were not realistic. It seems to me that Defra are refusing to be convinced by any scientific study, because the very act of studying it means it is not "field conditions". Do you see the paradox?

Be careful to also note Defra's use of the word "permitted", which echoes the get-out used by pesticide manufacturers, but ignores the fact that farmers have and will exceed allowed doses, either by accident or design.

Another question: why have France and Italy been persuaded that the evidence is sufficient to impose a suspension in the use of some of these pesticides, but not the UK?

Lastly, Defra states:

Regulation needs to be based on all the science. Existing field studies on neonicotinoids found there weren't any significant differences between hives exposed to treated crops and hives exposed to untreated crops.

But Prof David Goulson, at the University of Stirling and leader of the other study in Science, told me previously: "If they have done these studies, where are they? They are not in the public domain and therefore cannot be scrutinised. That raises the question of just how good they are."

There is one glimmer of hope in the Defra document, which was very quietly slipped out:

The government has already put new research in place to explore further the impacts of neonicotinoids on bumble bees in field conditions and to understand what levels of pesticide residues and disease in honey bees are normal. This work is due to finish in spring 2013.

Defra also states: "We are prepared to take whatever action the evidence shows to be necessary." It seems clear to me that sufficient evidence already exists to require action, but we can only hope the new work ends Defra's stalling.

Paul de Zylva, Friends of the Earth nature campaigner, sums it up well: "The government's failure to act on neonicotinoid pesticides is astonishing – there is still a massive question mark over the impact of these chemicals in declining bee populations. Pesticide company profits must not be put ahead of bees well-being."

Update 1015, 19 September: Prof Goulson has sent me this response, which speaks for itself:

Few experiments are perfect. In this situation, the perfect experiment would be to find and follow the fates of hundreds of natural bumblebee nests in landscapes with crops treated with neonicotinoids, and hundreds of control nests in an identical landscape without neonicotinoids. The latter does not exist, since these compounds are extremely widely used. That is why we dosed our bees in the lab, before putting them in the field.

I still think that ours is the closest anyone has come to doing a well replicated, controlled experiment to look at the effects of neonicotinoids on bumblebee nests in something approaching a natural setting. If our results are anywhere close to the truth, then they are pretty alarming.

Bee study lifts lid on hive habits

Bee study lifts lid on hive habits

Experiments on division of labour among honeybees reveal why some worker bees are foragers while others nurse their queens

Bees in a hive near Woking: the study is thought to be the first to show that reversible chemical markers on genes might drive different behaviours. Photograph: Matt Cardy/Getty Images

Experiments on the division of labour in honeybee hives have revealed why some bees do the waggle dance while others nurse their queens.

The roles require drastically different behaviours, with nurses feeding the larvae and performing royal grooming duties, and foragers navigating great distances and performing complex dance routines to point others in the direction of rich sources of nectar.

According to a report in the journal Nature Neuroscience, the job a worker bee does corresponds to distinct patterns of chemicals that latch on to and regulate certain genes in their brains.

Honeybees are born into their place in society. Those fed royal jelly as larvae emerge as queens and do little but lay eggs. The rest become worker bees and divvy up the jobs that need doing around the hive. While some worker bees remain at home, others take flight in search of nectar, pollen and other hive essentials. The entire honeybee workforce are genetically identical sisters.

But analysis of the worker bees' DNA revealed that foragers had one pattern of chemical tags on their genes, while those that stayed home had another. When bees swapped one job for the other, their genetic tags changed accordingly. Scientists call these patterns epigenetic states, because they work on top of the normal genetic code.

The study is thought to be the first to show that reversible chemical markers on genes might drive different behaviours in a living creature.

"If this is true in a bee it has to be partly true in us. Nature is pretty good at finding the simplest way to accomplish things with the least amount of energy," said Dr Andrew Feinberg, a senior author on the study and geneticist at Johns Hopkins University in Baltimore. "I'm not saying we're like big bees, but similar mechanisms must apply."

Feinberg and Dr Gro Amdam, a bee specialist at Arizona State University, studied a kind of chemical tagging called DNA methylation on honeybee genes switched on in the millimetre-cubed brains of 21 nurses and 22 foragers.

They found 155 regions of DNA where the epigenetic patterns between the two varieties of honeybee differed. Most of these regions are known to regulate the epigenetic patterns of other genes, to switch them on or off, or alter their function in other ways.

Having established differences between the foragers and nurses, the scientists forced a shift in the hive's workforce by removing the nurse bees while the foragers were away. After a few weeks, the hive had stabilised again, with around half of the old foragers now working as nurse bees.

DNA tests on these insects revealed that the chemical tags changed in bees that reverted from foragers to nurse roles. In all, the scientists found 107 gene regions where the chemical tags differed between the two. This suggests the different roles are intimately linked to the chemicals tagged on to the bees' genes.

"What we understand now is that the bee genome is like those images where you can see two things, like an old lady and a young lady. These epigenetic marks seem to outline those two women. Depending on which bee should come to life, the different sets of marks become active," Dr Amdam told the Guardian.

"These marks can change from one image to another and even back, and something like that has never been observed before in biology," she said.

Pesticide threat to bees to be investigated by parliament

Pesticide threat to bees to be investigated by parliament

A powerful group of MPs will quiz ministers on why, unlike in other countries, the mounting evidence of serious harm is not leading to action

Neonicitinoid pesticides can cause an 85% loss in the number of queens produced and a doubling in "disappeared" bees, those that fail to return from food foraging trips: Lena Ason/Alamy
On Wednesday, I accused the government of failing to act on the significant and growing evidence that neonicitinoid pesticides cause significant harm to bees. For my trouble, I was "mythbusted" by the department for environment, food and rural affairs (Defra).

But I am far from alone in my concerns and I can now reveal that a full parliamentary enquiry is going ahead into the matter. Joan Walley MP, who chairs the House of Commons environmental audit committee, a powerful cross-party group that acts as parliament's green watchdog, sent this letter to the Guardian on Friday.

Damian Carrington's blog on the government's response to recent research on the impact of insecticides on bee populations is timely (The silence of the bees). Last week the Environmental Audit Committee, which I chair, decided to undertake an inquiry looking at the effects of pesticide use in the UK on biodiversity with a specific focus on bees.

As Damian's blog pointed out, the use (and abuse) of evidence in policy-making and formulating regulation is clearly at the heart of the matter. But there are other issues that I want our investigation to examine. What monitoring is there of actual - rather than recommended - levels of pesticide usage? What are the potential impacts of these insecticides on human health? And should Defra be encouraging alternative pest-control measures, such as natural predators and plant breeding for insect-resistance, in a bid to make UK farming more bee-friendly?

We will be announcing details of the inquiry soon. In the meantime, Defra ministers may want to start doing their homework on pesticide policy and biodiversity, because we will be calling them before parliament to answer questions on these issues. In particular, we will be scrutinising the evidence behind the Government's decision not to revise pesticide regulations or follow other European countries in temporarily suspending the use of insecticides linked to bee decline.


I have very little to add to that, beyond hoping that the MPs can flush out the trials always cited by government and pesticide companies in defence of the chemicals, but which appear not to be in the public domain. The whole issue is very murky and the MPs will shed some very welcome light.

Everton blazes with wildflower meadows in time for the Liverpool Biennial

Everton blazes with wildflower meadows in time for the Liverpool Biennial

Two acres of the city have been turned into a colourful canvas, in the spirit of the meadows and wetlands which earned such praise at the Olympic Park

When you reach Liverpool on the M62, one of the first signs you see (along with one to Knotty Ash of Ken Dodd fame) directs you to theNational Wildflower Centre. This flourishing place now has a rival across the city in Everton as these pictures show.


They have been sown and landscaped in Everton Park by the artistRebecca Chesney following a research residency which she did at theYorkshire Sculpture Park over in West Yorkshire, near the birthplaces of both Barbara Hepworth and Henry Moore. Like the Sheffield University botanists who brought the meadows and wetlands of London's Olympic Park to such perfection in time for the Olympic and Paralympic Games, they are a blaze of colour at a key moment in Liverpool's year.

Commissioned by Landlife and the Arts Council, they will be in flower during the Liverpool Biennial openings this coming weekend, when Chesney willdiscuss them publicly in a temporary dome at the park with artist, landscaper and designer of 'edible gardens' Fritz Haeg and others on Sunday 16 September.


Part of their purpose is to encourage the city's growing population of urban bees and Chesney says:

They are already buzzing with bees and lots of other insects too. It's hoped that the meadows will remain on site for at least 3 years. This year the flowers are mostly annuals, but next year I'm hoping the perennials will dominate.


By the look of them, the wildflowers will win local support for a very much longer time in place, instead of the previous mown grass; and other northern cities will surely copy.

EU proposes to ban insecticides linked to bee decline

EU proposes to ban insecticides linked to bee decline

Three neonicotinoids, the world's most widely used insecticides would be forbidden across the continent for 
Three neonicotinoids would be forbidden from use on corn, oil seed rape, sunflowers and other crops across Europe for two years. Photograph: Narong Sangnak/EPA

Insecticides linked to serious harm in bees could be banned from use on flowering crops in Europe as early as July, under proposals set out by the European commission on Thursday, branded "hugely significant" by environmentalists. The move marks remarkably rapid action after evidence has mounted in recent months that the pesticides are contributing to the decline in insects that pollinate a third of all food.

Three neonicotinoids, the world's most widely used insecticides, which earn billions of pounds a year for their manufacturers, would be forbidden from use on corn, oil seed rape, sunflowers and other crops across the continent for two years.

It was time for "swift and decisive action", said Tonio Borg, commissioner for health and consumer policy, who added that the proposals were "ambitious but proportionate".

The proposals will enter EU law on 25 February if a majority of Europe's member states vote in favour. France and the Netherlands are supportive but the UK and Germany are reported to be reluctant.

"It's important that we take action based upon scientific evidence rather than making knee-jerk decisions that could have significant knock-on impacts," said the environment secretary, Owen Paterson. "That's why we are carrying out our own detailed field research to ensure we can make a decision about neonicotinoids based on the most up-to-date and complete evidence available."

Luis Morago, at campaign group Avaaz which took an anti-neonicotinoid petition of 2.2m signatures to Brussels, said: "This is the first time that the EU has recognised that the demise of bees has a perpetrator: pesticides. The suspension could mark a tipping point in the battle to stop the chemical armageddon for bees, but it does not go far enough. Over 2.2 million people want the European commission to face-down spurious German and British opposition and push for comprehensive ban of neonicotinoid pesticides."

Keith Taylor, Green party MEP for South East England MEP, said: "For too long the threat to bees from neonicotinoids has been dismissed, minimised or ignored. It is, therefore, good to see the European commission finally waking up. Bees have enormous economic value as pollinators and are vital to farmers. Let us hope that we're not too late in halting the dramatic decline in their population."

Scientific evidence has mounted rapidly since March 2012, when two high-profile studies found that bees consuming neonicotinoids suffered an 85% loss in the number of queens their nests produced and showed a doubling in "disappeared" bees who got lost while foraging. Neonicotinoids have been fiercely defended by their manufacturers, who claim there is no proof of harm in field conditions and by farming lobbies who say crop yields could fall without pesticide protection. Some neonicotinoid uses have been banned in the past in France, Italy, Slovenia and Germany, but no action has yet been taken in the UK. A parliamentary committee is currently investigating the impact of neonicotinoids on all pollinators and found evidence raising "serious questions about the integrity, transparency and effectiveness of EU pesticides regulation".

On 16 January, the European Food Safety Authority, official advisers to the EC, labelled the three neonicotinoids an unacceptable danger to bees feeding on flowering crops and this prompted the proposal produced on Thursday. If approved by experts from member states on 25 February, it would suspend the use imidacloprid and clothianidin, made by Bayer, and thiamethoxam, made by Syngenta, on crops that attract bees. Winter cereals would be excluded, because bees are not active at that time, and the suspension would be reviewed after two years. The European commission is also considering banning gardeners from using these neonicotinoids, although B&Q, Homebase and Wickes have already withdrawn such products from their garden centres in the UK.

"This hugely significant proposal promises a first, important step on the road to turning around the decline on our bees," said Friends of the Earth's head of campaigns Andrew Pendleton. "The UK government must throw its weight behind it. The evidence linking neonicotinoid chemicals to declining bee populations is growing. It is time to put farmers and nature before pesticide company profits. Ministers must act quickly to support safe and effective alternatives to chemical insecticides."

Bees and plants communicate via electric signals, say scientists

Bees and plants communicate via electric signals, say scientists


                                                     Electric fields could help bees detect flowers that have already
                                                           been visited and have lower pollen levels


Researchers suspect the plant's electrostatic force causes the bee's hair to bristle. Photograph: Diego Azubel/EPA
Plants use electric fields to communicate with bees, scientists have learned.

Bumblebees are able to find and decipher weak electric signals emitted by flowers, according to the study.

Tests revealed that bees can distinguish between different floral fields, as if they were petal colours. The electric signals may also let the insects know if another bee has recently visited a flower.

How bees detect the fields is unknown, but the researchers suspect the electrostatic force might make their hair bristle. A similar hair-raising effect is seen when placing one's head close to an old-style TV screen.

Flowers were already known to use bright colours, patterns and enticing scents to attract pollinators.

Electrical signals may provide a deeper level of communication, the scientists believe.

Study leader Professor Daniel Robert, from the University of Bristol team, said: "This novel communication channel reveals how flowers can potentially inform their pollinators about the honest status of their precious nectar and pollen reserves."

The research was published on Thursday in the latest online edition of the journal Science.

Plants are known to emit weak negatively charged electric fields, and bees acquire a positive charge as they fly through the air.

As a charged bee approaches a flower, the difference in electrical potential is not enough to produce sparks, but can be felt by the insect.

The researchers investigated the signals by placing electrodes in the stems of petunias.

They found that when a bee landed on a flower, the plant's electrical potential changed and remained altered for several minutes.

This could be a way of letting a bee know it is landing on a flower that has already been visited and lost its nectar, the scientists speculate.

To their surprise, they discovered that bumblebees can distinguish between different floral electric fields.

They were also quicker at learning the difference between two flower colours when electrical signals were also present.

"The co-evolution between flowers and bees has a long and beneficial history, so perhaps it's not entirely surprising that we are still discovering today how remarkably sophisticated their communication is," Professor Robert added.

• This article was amended on 26 February 2013 to remove an inaccurate statement that bees acquire a positive charge of up to 200 volts as they fly through the air. Two hundred volts as a value of potential, not a charge, is mentioned in the paper.