BL Talk science 26th June 2013 – Pollinators and pesticides: is there a plan bee?

Last week I went to a British Library evening event on pollinators and pesticides, which took a look at whether pesticides are the real culprit for the decline in bee numbers. The event only cost £5 and it included free wine and chocolate honeycomb covered sweets. Score!

Oh, and it had some very good speakers too, which is why I was there of course. Our chair was BBC Presenter and hobby beekeeper Bill Turnbull, with speakers Dr David Aston (Chairman, The British Beekeepers Association), Dr. Peter Campbell (Senior Environmental Specialist, Syngenta) and Dr. Lynn Dicks (Postdoctoral Research Associate, University of Cambridge).

Talk Science events are held by the British Library for researchers from academia and industry, policy makers, research funders, publishers and all those with a stake in science. You can follow the Science team on Twitter @ScienceBL, event hash tag #TalkScience. The team has since done a British Library science blog post on the event, which has a photo of me and a link to my blog – thanks guys!

This particular talk was being filmed for a Horizon programme due to be broadcast on Friday 2nd August, so you may spot me in the audience if you watch it! Bill Turnbull began by saying that he wanted “an informative rather than combative debate” – a sign that feelings would be running high.

The panel chatting before the debate began

The panel chatting before the debate began

David

Each panellist began by saying a little bit about themselves and their work. David was speaking on behalf of honey bees and identified weather and forage availability (both quality and quantity) as two of the biggest problems facing them.

According to David, 30 kilos of pollen are required by an average honeybee colony during a year (the equivalent of 15 bags of sugar) and 120 kilograms of nectar – just to survive, before the beekeeper comes along and removes any surplus honey.

He reminded us that beekeeping now requires a high degree of technical competence. Bees are wild animals, not domesticated creatures like sheep and cattle. They have their own minds and won’t always do what beekeepers want them to!

David has seen no evidence of harm to honey bees in the UK from neonicotinoids. He is worried about what alternative products will be used after the ban comes in.

Red pollen

Pollen stored in honey bee comb

Lynn

Lynn has expertise in ecology and conservation. She put bees as pollinators in the food chain into context with a few facts:

  • Bees are important pollinators because they consume pollen both as developing larvae and as adults (unusual in the insect world)
  • There are around 256 species of wild bees living in the UK: just one species of honey bee, 24 species of bumble bees… and the rest are solitary bees.
  • Hoverflies are important pollinators too. In some parts of Scotland, hoverflies are the most frequent pollinator visitors to flowers. There are 250 odd species of hoverflies in the UK and they eat pollen as adults. Of course there are also the wasps, beetles, butterflies and moths busy doing their thing too.

We have a good idea that wild bees have declined in diversity in the UK, but we don’t know by how much. Research published in Science journal in 2006 provided the first data available on bee numbers. However, we still don’t know how many individuals there are. We do have numbers for butterflies and moths – they are suffering ongoing declines.

For Lynn, the main problems are loss of flowers, loss of habitat, possibly climate change and diseases – “multiple, interacting threats”. She has four suggestions to help bees:

  • Farmers should start treating pollination as an essential agricultural input to invest in and think about how to manage their landscape for pollinators
  • We should protect habitat, both in urban and country areas
  • Reduce use of pesticides overall (use is actually going up slightly right now)
  • Find out how many wild bees and hoverflies there are. Hard as that might sound, Lynn says there are good techniques available which don’t cost much.

EDIT: Philip Strange, a scientist and writer, kindly left me a comment below with a link to a post by Lynn where she expands further on these points: Action for pollinators: things we can all agree on.

Bumble bees I photographed whilst on my lunch break near St Pauls Cathedral last week

Bumble bees I photographed whilst on my lunch break near St Pauls Cathedral last week

Peter Campbell

Peter was last to speak. No-one booed when he introduced himself as an environmental risk assessment scientist at Syngenta, a manufacturer and seller of pesticides, but I imagine some bristled a bit.

Obviously Peter has a particular angle to take on behalf of Syngenta, which is that neonicotinoid research studies in the past two years have mostly been carried out in labs rather than the field. Syngenta have been doing many field trials on honey bees themselves, which so far have found no risk to bees when the neonics are used properly.

They are currently doing a project on developing flowering margins, particularly on cereal farms, and have developed flowering mixes for field edges. The mixes have led to species which had disappeared previously returning. “Habitat is everything with wild bees… and varroa in the case of honeybees” Peter said.

Bombus hypnorum on rose

Bombus hypnorum on rose

Neonicotinoids

Things got spiky between the panel, particularly Peter and Lynn, as Bill came onto the issue of neonicotinoids. He brought up a study which had found that neonicotinoids left the directional memory of honey bees unaffected, but did have an effect on the landscape memory of bees trying to find their way home.

Peter’s response to this was that the study gave an unnaturally high dosage to bees, much higher than they would come across in the field. An experienced beekeeper in the audience agreed with him, using the analogy that experiments done so far seem to be like locking dogs in a garage with a running car for 24 hours and then blaming the internal combustion engine for their deaths. However Syngenta are doing work this year with RFID tags to try and see if landscape memory is a real issue.

David’s worry is that the neonicotinoids ban could lead to greater risk of exposure to other pesticides which farmers will turn to instead. Neonics were originally seen to be an environmental improvement on previous treatments. Peter added that oil seed rape may not be such a profitable crop without neonics and farmers may switch to growing cereals instead – but Lynn disagreed with this theory.

Lynn would like to see farmers become more reliant on integrated pest management (which the National Bee Unit inspectors recommends beekeepers carry out too). This involves using a range of methods during the year to keep pests at bay, rather than relying on one particular method of treatment.

According to Lynn, using systemic neonics in crop seeds means that farmers are no longer treating if and when pest attack is seen, but in advance of it happening – sounds good in theory but is not so great for the environment. Peter’s counter argument to this was that seed treatment allows farmers to target pests very carefully, and leads to less dosing of the field environment as a whole.

Debating. L-r: Bill, David, Lynn, Peter.

Debating. L-r: Bill, David, Lynn, Peter.

“Is the European Commission ban worthwhile?” asked Bill. 

The background to this is of course the European Commission’s two-year moratorium on the use of three neonicotinoid insecticides on “bee attractive crops”, following risk assessment reports from the European Food Standards Agency.

Lynn – the ban is a good place to start but two years is not long enough to assess its impact. However, scientists can do more analysis within the next two years to gather data  on the possible effects of neonics. She pointed out that whilst the case for an effect on honeybees is uncertain so far, lab studies using realistic doses have found a dramatic reduction in bumble bee queen production.

She believes we don’t yet know how realistic lab studies are, but if there is a risk it’s best for the EC to take a precautionary approach until we know more. This does mean making a subjective judgement. Two years gives some time for scientists to gather baseline data on bee numbers. A fantastic study named ‘Status and Trends of European Pollinators‘ (STEP) is currently going on to document the nature and extent of European pollinator declines. Knowing how many pollinators there are is necessary to tell if numbers go up or down as a result of this ban or any future ones.

Bumblebee melee

Moving on to less controversial subjects, Bill went on to ask “Why is weather such a problem now?” 

David replied that our weather today is a reflection of carbon dioxide levels twenty years ago. We are having increasingly extreme weather swings, with 2012 bringing unusually long periods of both wet and dry weather in the UK. In early 2012 water companies were running campaigns to save water, only to be followed by one of the wettest springs on record, with flooding in many parts of the country. Long periods of wet, cold weather can cause problems with unmated virgin queens.

“Colony collapse disorder. Is it here in Britain?” – Bill. 

David told the audience that the general BBKA view is CCD doesn’t occur in this country. Colonies do collapse, but not in the same way as reported in the US.

Bombus hypnorum on rose

Bombus hypnorum on rose

And finally, Bill’s last question was “What does the future hold for bees? Are you feeling optimistic?”

David – To be a beekeeper, you’ve got to be optimistic! We can all do things to improve forage and nectar sources. Weather and a lack of forage are critical factors for most insect species.

Lynn – optimistic about the huge amount of interest in pollinators and the number of young scientists being trained. More funding money is becoming available from governments. During the past 20-30 years insects have not been looked after well – this may be starting to change.

Peter – we need biodiversity. Helping pollinators is all about habitat. Environmental subsidies will really help pollinators going forward. We also need more research into practical solutions, such as fighting varroa – the biggest problem facing honey bees now.

Bombus hypnorum on rose

My conclusions

Not being a scientist or farmer myself, and without having read through much of the current research, it was hard for me to form an opinion as to whom was right – Lynn that neonics pose serious risks to bumble bees based on the research, or Peter that lab studies are too unrealistic and do not reflect field conditions.

Knowing that Peter must defend Syngenta’s interests as part of his job does make me skeptical. It’s easy for Syngenta to say that lab tests don’t relate to field doses, knowing full well that it’s very difficult to carry out tests in the field because bees forage over such large distances. On the other hand, I agree with Peter that providing good bee-friendly forage and researching solutions to varroa is very important – even though I suspect he may be bringing up these factors to distract from the neonics issues!

What do you think, was the EC right to put the ban in place?

About Emily Scott

I am a UK beekeeper who has recently moved from London to windswept, wet Cornwall. I first started keeping bees in the Ealing Beekeepers Association’s local apiary in 2008, when I created this blog as a record for myself of my various beekeeping related disasters and - hopefully! - future successes.
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30 Responses to BL Talk science 26th June 2013 – Pollinators and pesticides: is there a plan bee?

  1. I think the ban is a good thing. I fear it is a bit like cigarettes – people spend ages saying all the evidence could mean something else when really, nicotine is a nasty. I think we need to be much more careful introducing anything that gets sprayed on foods and enters the food chain of pollinators these days than in the past because farms are huge, pollinators are already struggling and if we tip the balance too much the wrong way, we’ll all lose out. A bit of caution and time to do some impartial studies sounds sensible to me.

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    • Emily Heath says:

      Thanks for your thoughtful comment. Australia was brought up as an example of somewhere where neonics are used but honey bees are doing well. However you guys have such good weather and no varroa, so I think it’s not a good comparison. Also, no bumbles in Australia, which seem to be the type of bee which most conclusively suffers from neonics.

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  2. Bruce says:

    Love your photos of “Humble Bees” (their former name used by Darwin). I have heard way too many scientists payed by Sygenta, Bayer, Monsanto … claim for years that their product (i.e. agent orange, ddt, dioxins, pcbs …) was absolutely safe similar to the cigarette company scientists in the 60’s and 70’s. It constantly amazes me what people will do for money. Systemic neonicotinoid pesticides effect the nervous system of bees and whether lethal or sublethal the result is devastating. Studies have proven this (http://strathconabeekeepers.blogspot.ca/p/the-beekeepers-library.html#insecticides and bees). The scientist says it’s safe if applied properly. In Canada and the U.S. it is rarely applied safely. Countless beekeepers have lost hundreds if not thousands of hives when the genetically modified seed containing the neonicotinoid is planted (http://strathconabeekeepers.blogspot.ca/2012/06/neonicotinoids-kill-bees-in-ontario.html). This is just one of countless examples of the effects of neonicotinoid pesticides on bees. The dust containing the pesticide can carry a mile or more in the wind and has resulted in several commercial beekeepers losing most of their hives. Being a systemic pesticide the morning dew on the plant which bees drink from may contain elements of the pesticide. Bees wax in the hive is the perfect receptor for environmental particulates and studies have shown traces of over 30 different types of pesticides, herbicides and fungicides. How many scientists from Sygenta have studied the accumalative effect of this cornicopia of toxins. Bottom line they are payed to defend the product their employer is producing. While I believe that available forage and stopping the mass transport of bees worldwide (supporting local bee breeding) is vitally important as important is stopping the use of neonicotinoids and the reduction of all agrochemicals.

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    • Emily Heath says:

      I suspect the money paid is rather good at Syngenta!

      Thanks for the links. Agree with you that pesticides are not always applied according to the instructions. The terrible case of the 50,000 bumble bees killed in a car park recently proves that. In the UK farmers are supposed to inform local beekeepers before spraying but as farmers are busy people I expect that doesn’t always happen.

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  3. I too am very skeptical. I admire Peter for speaking and defending, but I believe it is the cocktail of chemicals bees come across in their daily forage. Any one used properly may have little overall effect, but in synergistic combination, they all have detrimental effect to a greater degree. Certainly I have no real basis for my belief since all pesticides and neonicotinoids are not studied in the same manner, and like you, I am not a scientist or farmer. If only all chemicals could be curtailed, what a better place for all wildlife, even us.

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    • Emily Heath says:

      Going organic would be best for all of us. Wish governments could pass a law requiring all farms to go organic, so that organic farmers weren’t at a price disadvantage when selling to consumers. Driving less is important too – a lot of the corn produced in the US is used for biofuel added to petrol, including petrol sold in the UK.

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  4. jeffollerton says:

    Thanks for an interesting summary of the event. However as a scientist who has worked with wild pollinators for over 20 years I have to take issue with David Aston’s comment that “[honey bees] are wild animals, not domesticated creatures like sheep and cattle.”

    That’s simply not true – they are exactly like domesticated animals! Honey bees are not native to Britain, or to most of the world for that matter. The “British” honey bees are domesticated varieties and are native in the same way that Tamworth pigs or Highland cattle are “native”. Honey bees have been genetically selected for particular behavioural traits, a sure mark of domestication. Yes, they have “a mind of their own” and may leave the hive and go feral. But so too do domesticated pigeon varieties.

    This might seem like a petty point but it’s important. The issues affecting honey bees have been conflated in the public’s mind with the decline of wild bees and other pollinators. They are largely separate issues and comments such as David’s do not help public understanding of this fact.

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    • Nick Holmes says:

      I thought honey bees ARE native to britain, although they have been bred with various breeds of apis mellifera (ie linguistica, etc) to produce the ‘modern’ ‘breeds’, apis mellifera mellifera is a British native, isn’t it?

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      • jeffollerton says:

        The only study that I’m aware of that has addressed this question is Norman Carreck’s paper from 2008. He is convinced that A. m. mellifera is native to Britain but all of the evidence he presents is circumstantial and the earliest archaeological remains of honey bees are all associated with human settlements. Even if honeybees were originally native to Britain, the present situation, in which honey bees have been selectively bred and hybridised, is akin to using Tamworth pigs as evidence that wild boar are native.

        However for me the most compelling evidence that honey bees are not native is ecological: despite their generalist nature and ability to form large colonies when managed, out in the “wilds” of Britain the bees do not do particularly well. “Wild” bees are never very abundant (compared with some bumblebee species, for instance) and feral colonies in natural settings are few and far between and tend not to persist for long in my experience.

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        • Emily Heath says:

          Certainly Apis mellifera is native to Europe, though when it first arrived in Britain is probably now lost in the mists of time. Various Asia melliferasubspecies also occur naturally in Africa and the Middle East, while the giant honey bee Apis dorsata is native to East Asia and Apis cerana orignated in Asia. So many continents do naturally have honey bees of one type or another.

          How recent are your experiences that honey bees do not last long in the wild? Many older beekeepers tell me that feral colonies used to be more widespread before the arrival of varroa.

          I think what David was getting at is that honey bees are not easy creatures to control, or for that matter study. Sheep can be herded by dogs, cows can be kept in hedged fields, pigs in pens. But honey bees rise supremely free, flying above human constraints. We have no way to communicate with them either – we cannot whistle at them like sheepdogs and get them to do our bidding.

          There is no difference in behaviour between a feral honey bee colony and one kept in a hive by a beekeeper. Whereas a feral cat reacts quite differently to humans than a tame one.

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          • jeffollerton says:

            It’s recent experience but from talking to an old bee keeper! Would be good if there was some hard evidence on this question. But in the surveys of pollinators I’ve done over the past 20 odd years, honey bees are never especially abundant as flower visitors, except where there are hives in the vicinity.

            Regarding your initial comment, Emily – Europe is a large continent! Whether the species is native to northern Europe, or whether it was naturally only confined to the southern part, is an unanswered question.

            I take your last point but it very much depends on where on the continuum from “wild” to “domesticated” a species sits. Honey bees are further towards the “wild” end, certainly, compared to the mammals you cite. But selective breeding for desirable characteristics means they are genetically different from “wild” ancestors.

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            • Emily Heath says:

              Thanks for your comments, these are interesting points. I think the selective breeding has been fairly minimal in the case of honey bees, simply because before artificial insemination it was hard to selectively breed. The queen bee flies where she will and mates with multiple drones. However queens from more aggressive colonies can be destroyed and replaced with calmer queens, so it’s true that some selective breeding has been achieved. Would love to know how different honey bees are now from a few hundred or thousand years ago.

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    • Emily Heath says:

      I do agree with you that solitary bees, bumbles and other pollinators are far more vulnerable than honey bees. Apis mellifera mellifera is not going to go extinct any time soon, whereas that is a real possibility for some of our bumble and native bee species. It’s great that you’re on their side.

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  5. Helen says:

    I couldn’t make it to the meeting, so I am grateful for this good, clear reporting of the event. As a gardener, I am coming round to the idea that the temporary ban of neonic use by farmers is a good idea, to enable additional thorough research to take place. I firmly believe (based on absolutely no research whatsoever!) that any ‘damage’ done to the bee population by gardeners is a mere drop in the ocean.

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    • Emily Heath says:

      Thanks for your comments. I’m not sure what most gardeners do – I find it disturbing that neonics are sold in garden centres – are they really necessary for garden flowers? I think gardens are brilliant for urban bees, as they can provide a great diversity of flowers not found amongst rural fields of mono crops. Would be great if the government offered people incentives not to concrete over their front gardens.

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  6. Alex Jones says:

    My opinion is that the field trials of an independent body would be the only one I would consider as authentic and reliable. However Syngenta is useful as a source in context.

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  7. Nick Holmes says:

    I find it interesting that Dr David Aston was chosen to talk ‘on behalf of honey bees’ when he is of a very select minority of beekeepers and public persons that don’t think neonicotinoids are to blame for the issues. Might have been better to have a balance represented of a beekeeper who does think they are the cause of problems. Poor show BBC, lacking in balance. I continue to be impressed with the scare tactics of saying ‘maybe farmers will use something worse now’ without evidence or naming what they will turn to that is so bad.

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    • Emily Heath says:

      To be fair, ‘on behalf of honey bees’ was my phrase, not David’s, and although the event was being filmed by Horizon it was organised by the British Library. As well as being Chairman of the BBKA David is certainly a bee expert and has co-written some excellent books on bee health and foraging activities.

      At the ‘A Future without bees’ talk at the Southbank Centre I went to recently (posted about at https://adventuresinbeeland.com/2013/06/02/a-future-without-bees-a-talk-at-the-southbank-centre/) speaker Karin Alton told us that currently farmers do two sprayings of pyrethroids a year, but when the ban comes into force they are likely to switch to three sprayings, with an extra time in Spring. Pyrethroids don’t last very long in the area sprayed – a week or two – but unfortunately do kill fish if they seep into ponds or rivers.

      Talking to beekeepers I know, not many people think the neonics are the sole cause of bee problems. Destruction of habitat for bees generally and the varroa mite for honeybees are two massive issues which won’t go away no matter what pesticides are used.

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  8. Thank you so much for this balanced summary of the talk. I agree with Jeff Follerton that it does not appear that the public understands that this is not just a problem for honey bees. We are told that gardens may provide oases for the wild pollinators in this time of dearth for natural environments but how many gardeners renounce using pesticides and herbicides on their gardens and lawns? Is it all up to the crop farmers?

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    • jeffollerton says:

      Good point, use of chemicals in gardens is wholly unregulated and collectively could be doing a lot of harm. It’s “Ollerton” by the way 😉

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    • Emily Heath says:

      It’s bizarre that some home gardeners feel the need to spray their garden full of chemicals. Hopefully it’s a minority of people doing this, but the garden centres and supermarkets must be selling these sprays to someone. Some people still use slug pellets even though their effect on hedgehogs is well known. Wish everyone ran wildlife friendly gardens like yours!

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  9. Thanks for an interesting post, Emily.
    I wanted to pick up on a few points in the discussion:
    1. David Aston, chair of the BBKA, said he had not seen any evidence of effects of neonics on honey bees. However, lack of evidence is not evidence of lack. We shouldn’t conclude that neonics are safe because we haven’t seen any effects of them.
    To take an example, there have been huge winter losses of bees in the UK over the 12/13 winter and everyone has nodded sagely and concluded that this is due to the bad weather. We cannot know for certain what combination of factors caused these winter losses (certainly weather, probably Varroa etc) and neonics may or may not also contribute.
    Only by doing proper controlled experiments and providing evidence, can conclusions be drawn. There is no question that neonics can kill bees, what we need to do is to find evidence for or against these chemicals when they are used “properly”.
    2. Lynn Dicks writes very wisely on these issues. Here is her view on the economic value of neonics (http://www.valuing-nature.net/blogs/lynn-dicks/how-much-are-neonicotinoids-worth-european-economy) which doesn’t agree with the Syngenta view.
    Here she is on the need to reduce pesticide etc use more generally (http://www.valuing-nature.net/blogs/lynn-dicks/action-pollinators-things-we-can-all-agree)
    3. Peter Campbell from Syngenta said that they had tested the neonics and they were safe for bees. Where is the evidence, has it been published? When an academic scientist performs a study they, rightly, want to publish and it must be subjected to peer review before publication occurs. To the best of my knowledge much of the data from pesticide companies has not been subjected to this process (http://www.parliament.uk/business/committees/committees-a-z/commons-select/environmental-audit-committee/news/pollinators-pesticides-report/). It is not enough to say we have done the study and it shows this or that; it needs to be out there to be dissected and scrutinised. Syngenta have been very quick to condemn the so-called lab-based studies on neonics when they are published; they should let their own data be open to similar scrutiny.
    In fact, the reason EFSA recommended a ban on neonics was because they came to the conclusion that there were insufficient data available on their safety (http://www.efsa.europa.eu/en/press/news/130116.htm)
    4. There is good evidence that neonics are more harmful to bumblebees than honeybees. Bumblebees are important pollinators and we should support these insects alongside the honey bees. EFSA were very concerned that there were no data on the safety of neonics for bumblebees.

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    • Emily Heath says:

      “David Aston, chair of the BBKA, said he had not seen any evidence of effects of neonics on honey bees. However, lack of evidence is not evidence of lack. We shouldn’t conclude that neonics are safe because we haven’t seen any effects of them.”

      – Agreed. This is the angle Lynn was taking too, that if we’re unsure we should take precautionary steps to halt their use while we do further research. Thanks for the links to her posts.

      I was writing frantically but did miss some parts of the debate out. I remember Peter mentioning that Syngenta are looking into publishing some of their research soon though.

      Like you I am concerned about bumbles, more so than honey bees. I find it startling how little research was done into the effects of neonics on them before these products were authorised for use.

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  10. What a fascinating debate!

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  11. Pingback: Are honey bees native to Britain? And does it matter? | Jeff Ollerton

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