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Thread: Video lecture about risk profile of neonicotinoid insecticides

  1. #1

    Default Video lecture about risk profile of neonicotinoid insecticides

    Dear fellow beekeepers,

    on Frebruary 16, 2011, the dutch toxicologist Dr. Henk Tennekes gave a lecture at the Institute of Public Health, University of Heidelberg (Germany). This lecture is about "Toxicity as function of exposure time - Risk profile of neonicotinoid insecticides".

    It was originally given in german, but yesterday I visited him to record an english version of his lecture for the international beekeeping community.

    You can see and listen to this video on youtube:

    http://www.youtube.com/watch?v=M4RIDWuCN-A

    Greetings from Germany,

    Klaus

  2. #2
    Administrator gavin's Avatar
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    Thanks very much for sharing this Klaus, very interesting. It certainly gives a perspective on environmental pollution that needs to be taken seriously. I guess that over the coming days and weeks we will be discussing the implications of the talk here.

    Do you know where we can see the raw data or better quality slides for the Dutch Water Boards study of imidacloprid in surface water?

    best wishes

    Gavin

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    Hi Gavin,

    Dr. Tennekes gave me some sheets and in the later evening I'll change it to pdf and upload it to my server. I will post a message.

    Greetings, Klaus

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    Banned Stromnessbees's Avatar
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    Well, I know I have gone awol for a while, but for this thread it seems worthwhile to creep out of the woodwork.

    For those who don't have the patience to watch the whole video I have copied the page with the conclusions (from 25:41):

    Conclusions:


    • The mode of action of neonicotinoid insecticides derives from almost complete and virtually irreversible blockage of postsynaptic nicotinic AcetylCholine-Receptors (nAChRs) in the central nervous system of insects.



    • The toxicity of neonicotinoids to arthropods is reinforced by exposure time. Their dose : response characteristics are strikingly similar to those of carcinogens. Thus, there may not be a safe level of exposure.



    • Imidacloprid is persistent and mobile in soil and prone to leaching.



    • The contamination of surface water with imidacloprid is massive in some parts of Holland.



    • Of the 13 components of agricultural intensification, only the use of insecticides and fungicides had consistent negative effects on biodiversity (wild plant, carabid and bird species).



    • Surface water contamination with Imidacloprid correlates with reduced Diptera (Flies and Midges) abundance.



    • Strong decline of butterflies since the introduction of neonicotinoid insecticides.



    • Many invertebrate-dependent bird species (in very different habitats) are declining, some are now extinct.
    As Gavin points out, the quality of the clip is poor, so if you want to just watch the essence of the talk rather than an extended chemistry lession, I recommend listening from 12:20, when he gets to the biological implications for insects and birds.

    http://www.youtube.com/watch?v=M4RIDWuCN-A

    So, as there 'may not be a safe level of exposure' to neonicotinoids, what are we going to do?
    Last edited by Stromnessbees; 25-02-2011 at 01:10 PM.

  5. #5

  6. #6

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    Stromness wrote:
    * The toxicity of neonicotinoids to arthropods is reinforced by exposure time. Their dose : response characteristics are strikingly similar to those of carcinogens. Thus, there may not be a safe level of exposure.
    * Imidacloprid is persistent and mobile in soil and prone to leaching.
    I recommend listening from 12:20, when he gets to the biological implications for insects and birds.
    http://www.youtube.com/watch?v=M4RIDWuCN-A
    So, as there 'may not be a safe level of exposure' to neonicotinoids, what are we going do?
    .................................................. ......................
    Hi Doris
    What to do? Ban the offending material! As I have been advocating for many years!
    Chris Connolly’s pending important research should highlight just how much Scotand’s bee are at risk for the burgeoning use of these toxic systemic neonicotinoids

    Eric

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    Senior Member Jon's Avatar
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    Quote Originally Posted by Eric McArthur View Post
    What to do? Ban the offending material! As I have been advocating for many years!
    Just remember that if you ban neonics you are in effect voting to bring back organophosphates, carbamates and pyrethroids.

    Doris and Eric. I would be interested in hearing why you think it is better to use these older pesticides rather than neonicotinoid pesticides. we live in the real world and pesticide use will continue even if neonicotinoids are banned. Neonicotinoids are also known to be much less harmful to one important species - the human. Pity the 3rd world agricultural workers who are obliged to spray much more dangerous chemicals on crops and also over themselves in the process.

    It's easy to get on your high horse if you don't have to live with the consequences like some others have to.

    So, as there 'may not be a safe level of exposure' to neonicotinoids, what are we going to do?
    Tennekes is just one opinion and it is by no means mainstream.
    There is an overwhelming body of evidence which suggests that neonicotinoids are not particularily harmful to bees and other pollinating insects.
    There is not a single field study carried out anywhere in the world which has demonstrated that neonicotinoid pesticides are harmful to bees - and by God a lot of people have been motivated to try and demonstrate this.
    We wait on the C Connolly study with bated breath, but the design looks to be much less rigorous than many which have been carried out before, so it is debatable what it might show. As Roy Keane said when he walked out of Ireland's doomed 2002 world cup campaign. Fail to prepare, prepare to fail!
    Last edited by Jon; 28-02-2011 at 11:17 AM.

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    Administrator gavin's Avatar
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    Hi Doris

    Lovely to see you back! I hope that you stick around. There is a lot in that presentation to discuss.

    This business about 'virtually irreversible blockage of postsynaptic nicotinic AcetylCholine-Receptors (nAChRs) in the central nervous system of insects.'

    I had a look last night at the neurobiology literature. It is packed with jargon but if you persist it makes sense. Here is one paper I found that comments on the binding of imidacloprid to receptors, and it seems that you can wash off the imidacloprid within 20 mins with saline. That doesn't seem to square with Tennekes' comments apparently based on a Bayer document. I thought that we weren't meant to believe Bayer propaganda anyway!

    Buckingham et al 'Imidacloprid actions on insect neuronal acetylcholine receptors'

    best wishes

    Gavin
    Last edited by gavin; 28-02-2011 at 06:28 PM. Reason: Fixing URL

  9. #9

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    Hi All
    The current stramasch which is surrounding Chris Connolly’s pending research seems to be now bordering on the lunatic – the correspondence which has been generated and distributed beggars belief.
    The crux of the issue is that continuing research requires to be done to prove/disprove the current fears/controversy relative to the neonicotinoids. This proposed work is hopefully only one piece in a very adversarial issue which has to be resolved –lest the worst fears of the anti neonicotinoid lobby be realised.
    The funding is available let’s get behind the work in hand and stop this stupid bickering which to all intents and purposes is a mindless personality conflict – one sided as far as the evidence points!

    Eric

  10. #10

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    All,

    I found the Pdf presentation a bit of a shotgun approach to the subject in trying to link a range of adverse affects on biodiversity to the use of neonicitinoids over the past two decades. While I don’t deny for a minute that there isn’t evidence indicating neonicitinoids have an affect on a range of species, I do suggest it’s too simplistic to decree that these particular pesticides are wholly responsible for the demise of a wide range of our animal life.

    I’ve lived and worked on the Western Isles and it wasn’t neonicitinoids that killed of Corncrakes it was modern crofting/agricultural methods of crop harvesting allied to introduced mink and hedgehogs. In a similar vein, large scale and expanding monoculture allied to intensive farming methods which is tied into the removal of hedgerows and loss of habitat will have had a fundamental affect on all indigenous bird species.

    While it’s fairly obvious that insecticides and fungicides are likely to have a negative affect on biodiversity, in part isn’t that exactly their purpose? Why are we surprised that that they will have a dilatory effect on part of an ecosystem. We’ve been having an adverse effect on our environment since time immemorial – did not the ancient Greeks use sulphur as a pesticide?

    If we accept neonicitinoid use at all, it is the management and ancillary effects of their use that we should focus on. From that we can decide on the overall efficacy of their use and if science, need for food production and hopefully ethics dictates otherwise – then ban them. However, I’ve yet to see anything posted on the SBAi site that, as yet, convinces me that these systemic pesticides should be banned outright.

    In a previous thread I noted the lack of hard evidence presented by those who want neonicitinoids banned immediately. Alternatively,

    ‘In a meta-analysis of fourteen published studies of the effects of imidacloprid on honey bees under laboratory and semi-field conditions that comprised measurements on 7073 adult individuals and 36 colonies, fitted dose–response relationships estimate that trace dietary imidacloprid at field-realistic levels in nectar will have no lethal effects, but will reduce expected performance in honey bees by between 6 and 20%.’

    A meta-analysis of experiments testing the effects of a neonicotinoid insecticide (imidacloprid) on honey bees. James E. Cresswell, Ecotoxicology Nov 2010

    Not far from Holland,

    ‘Despite a high percentage of hives containing residues of imidacloprid [e.g. in France, more than one hive in two has residues of imidacloprid and its metabolite 6-chloronicotinic acid in the pollen, 30% in honey and 26% in bees (Chauzat et al., 2009)], the level of exposure is sub-lethal with no obvious effect on mortality (Schmuck et al., 2001; Nguyen et al., 2009).’

    Interactions between Nosema microspores and a neonicotinoid weaken honeybees (Apis mellifera) Cédric Alaux, et al Environmental Microbiology (2009)

    What the study does note, perhaps not surprisingly is the synergistic link between Nosema and imidclororid. However in Greece, ‘another interesting finding was that crop protection insecticides were not detected in honey in the majority of the cases. To the contrary, the most important source of contamination proved to be the acaricide coumaphos, which is used by apiculturists for the treatment of Varroa mite.’

    Bee Honey as an Environmental Bioindicator of Pesticides’ Occurrence in Six Agricultural Areas of Greece. George Balayiannis & Panos Balayiannis Arch Environ Contam Toxicol (2008) 55:462–470.

    Perhaps if links to the data/studies referred to in the video presentation and attachment were provided a more meaningful debate could develop. As far as the immediate banning of neonicitinoids is concerned the evidence, as presented in this thread, is certainly not one sided.

    Alex

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