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Thread: Another plethora of neonicotinoid articles today...

  1. #11
    Senior Member Jon's Avatar
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    Hi Neil
    Cresswell has come up a couple of times on this forum if you google. He did some sort of literature review of all the published papers on neonicotinoids and found some evidence for a reduction in colony vitality but nothing really significant. The papers he was looking at were lab studies rather than field trials which I think is the key feature to look for in any of the chatter about pesticide effects.

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    Senior Member chris's Avatar
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    Quote Originally Posted by Jon View Post
    The papers he was looking at were lab studies rather than field trials which I think is the key feature to look for in any of the chatter about pesticide effects.
    Hi Jon,
    Back in October, I received a mail telling of the work done by Madeleine Chagnon and Monique Boily at UQAM (Quebec). Basically, they had , in a 3 year research program, firstly demonstrated that bees subjected to known doses of a neonicotinoid insecticide developed brain enzyme modifications that caused flying; orientation; and communication problems. In fact the same stuff as shown elsewhere.
    They then studied the impact of this insecticide on bees foraging freely in the fields, where they obviously didn't know the quantity of insecticide ingested by the bees. They analysed 6000 !! bees that they took in 6 regions of Quebec. The hives had been placed near to fields where the pesticide had been used on maize, and also near to fields of organically grown maize, and in areas far away from these cultures.
    The operation consisted in catching the flying bees and killing them rapidly by placing them on dry ice. They were then conserved at – 80°c until their brain enzymes could be analysed. The researchers noted that the bees which foraged in the fields where neonicotinoids were used on the crops showed the same modifications as those that had been exposed to the pesticide in the laboratory.

    The research results have been submitted to the minister of agriculture. I have no idea if they have been published yet.
    Last edited by chris; 15-04-2012 at 06:42 PM. Reason: "ignore" was ambiguous

  3. #13
    Senior Member Jon's Avatar
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    Is this the same e-mail you got.

    http://www.mapaq.gouv.qc.ca/SiteColl...ure/807010.pdf

    I can read enough French to get the gist of that and there is always google translate when you get stuck.
    It would be nice to have more details of the methodology of the study.

    I noticed it said that other pesticide families such as carbamates and organophosphates affect bee brain enzymes as well.
    The main point this study is making seems to be that this could be a useful methodology for others to adopt with field studies.
    That's interesting as the RFID transmitters used in the recent Henry study also looks like a very useful new methodology for studying pesticide effects in the field.
    There is a definite need to move on from the lab studies as I do not think they prove a lot.

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    Senior Member chris's Avatar
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    It concerns the same work, though what I received was even more basic, which is why I would have liked to see a published paper.

    "I noticed it said that other pesticide families such as carbamates and organophosphates affect bee brain enzymes as well."

    Yes, but these families inhibit the AChE whereas the neonicotinoid increased its activity, which is why its use as a biomarker (is that English?) can be extented.So there is no confusion as to which pesticide is having the effect.

    I agree that *in the field* studies are important, but there are soooo many variables involved. But then,too many lab studies just end up with a situation where someone like Bonmatin rearranges what he has already done and claims it to be a new breakthrough. He wasn't even a recognized researcher- ha was somebody whose main ability was to put together a project, and arrange its funding.
    Last edited by chris; 16-04-2012 at 11:56 AM.

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    Administrator gavin's Avatar
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    This is all interesting guys. Of course, seeing an effect doesn't (necessarily) mean that something bad is happening. For example, honeybee workers are said to metabolise imidacloprid so that it has a half life of 5 hrs in their bodies, and the metabolites also get metabolised to extend the half life of all products to 24 hrs. The exposure to small doses will give a response, and part of that response will be enhancing the mechanisms to deal with the challenge.

    I'm reminded of one of the US bee researchers (forget her name for now) who looked at gene expression alterations in CCD-affected and non-CCD affected colonies. She seemed surprised that there was *not* a difference in expression of genes responsible for detoxifying pesticides. That seemed to be a sign that CCD was not strongly linked to pesticide exposure - similar to some of the Penn State work that looked for correlations between residues in CCD and non-CCD colonies.

    G.

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    Quote Originally Posted by Jon View Post
    Hi Neil
    Cresswell has come up a couple of times on this forum if you google. He did some sort of literature review of all the published papers on neonicotinoids and found some evidence for a reduction in colony vitality but nothing really significant. The papers he was looking at were lab studies rather than field trials which I think is the key feature to look for in any of the chatter about pesticide effects.
    Yep, I'd come across him a few times in the usual toing and froing but having the guy stand up and run through a few things put some useful and interesting context of what, at the end of the day, is quite a dry subject and can be difficult from a lay perspective to put proper context on.

    For what it's worth and despite finding it tiresome to have to disclaim every bloody post on this, it wasn't a "nothing to worry about, carry on" talk, more one of applying critical thinking and giving background information to a lot of the headlines and research that is about at the moment.

    One of the papers has a nice little graph that appears to quite clearly demonstrate that a colony losing its foragers at the numbers the research appears to indicate collapses. Prior to bringing that up there was a straw poll taken of what a room full of beekeepers would consider a normal sized colony in terms of number of bees (settled on 30,000 as a reasonable number), non scientific for sure, but feed that number into their model rather than theirs and instantly the colony no longer collapses. Weakened yes, but it doesn't collapse.

  7. #17
    Senior Member Jon's Avatar
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    What number of bees were they assuming in the theoretical colony size?

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    I don't have my notes with me and I'm not sure I have the exact figure, the size on the graph parameters that I saw I believe was 27,000. I understood his point was the loss of foragers was observed, everything else was an estimate built into their model, tweak one of those estimates and the results change dramatically.

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    Senior Member chris's Avatar
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    Quote Originally Posted by gavin View Post
    For example, honeybee workers are said to metabolise imidacloprid so that it has a half life of 5 hrs in their bodies, and the metabolites also get metabolised to extend the half life of all products to 24 hrs.
    Salut Gavin. I'm trying to understand this. If the bees affected by neonicotinoids are disoriented and have flight problams, many don't make it back to the hive. So someone who looks at these bees will only be seeing those that were not effected enough to prevent them returning.And so their results will be biased because the sample is not a typical cross section of foragers. With the *kill em n ice em* technique, the cross section is more representative because it includes those that wouldn't have made it back. And maybe these bees didn't metabolise so much, or perhaps they took bigger doses than previously suggested. Is this so?

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    Senior Member chris's Avatar
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    Quote Originally Posted by gavin View Post
    For example, honeybee workers are said to metabolise imidacloprid so that it has a half life of 5 hrs in their bodies, and the metabolites also get metabolised to extend the half life of all products to 24 hrs.
    Salut Gavin. I'm trying to understand this. If the bees affected by neonicotinoids are disoriented and have flight problams, many don't make it back to the hive. So someone who looks at these bees will only be seeing those that were not effected enough to prevent them returning.And so their results will be biased because the sample is not a typical cross section of foragers. With the *kill em n ice em* technique, the cross section is more representative because it includes those that wouldn't have made it back. And maybe these bees didn't metabolise so much, or perhaps they took bigger doses than previously suggested. Is this so?

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