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  1. #1
    Join Date
    Mar 2013
    Location
    Eugene, Oregon
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    14

    Default The Case Against Imidicloprid

    Please bee folk, I did a little playing with graphs and looked at various toxicity data on Imidacloprid and plotted on log-log graph to find the power law. It's disturbing to say the least. If you are wondering why we don't see residue in collapsed colonies, the answer is that the effects happen at unobservably small chronic doses.

    The post is here: http://squashpractice.wordpress.com/...-imidacloprid/

    We've got to follow the Europeans and get rid of this stuff!

  2. #2
    Join Date
    Jan 2010
    Location
    Stromness, Scotland
    Posts
    122

    Default Re: The Case Against Imidicloprid

    An excellent article, thank you for posting it!

    The link at the bottom to the work of Rosemary Mason should be followed up as well.
    I was lucky to have Rosemary visit our farm last year, to see a prime habitat of the endangered Great Yellow Bumblebee.

  3. #3
    Join Date
    Mar 2013
    Location
    Orkney,Scotland
    Posts
    9

    Default Re: The Case Against Imidicloprid

    Very interesting, will follow the links at the bottom of the article to find out more.

  4. #4
    Join Date
    Feb 2006
    Location
    Herrick, SD USA
    Posts
    4,043

    Default Re: The Case Against Imidicloprid

    This is an interesting theory and may well have some validity. It does, though, also seem to be a convenient means for keeping alive the theory that what cannot be detected is actually the problem. It would also seem to suggest that there would only be a single narrow window for neonic exposure. Is that plausible? Maybe, maybe not. I would suggest that if someone is to actually prove such a theory that they need actual data proving this rapid rate of metabolization and excretion.
    "People will generally accept facts as truth only if the facts agree with what they already believe."- Andy Rooney

  5. #5
    Join Date
    Mar 2013
    Location
    Eugene, Oregon
    Posts
    14

    Default Re: The Case Against Imidicloprid

    Quote Originally Posted by jim lyon View Post
    This is an interesting theory and may well have some validity. It does, though, also seem to be a convenient means for keeping alive the theory that what cannot be detected is actually the problem. It would also seem to suggest that there would only be a single narrow window for neonic exposure. Is that plausible? Maybe, maybe not. I would suggest that if someone is to actually prove such a theory that they need actual data proving this rapid rate of metabolization and excretion.
    This is not a theory. All I was doing is fitting existing data to a convenient toxicity model and extrapolating to the age that bees normally live. The fact the the model works well with the neonics with other species, and fits published bee toxicity data, suggest that actually the chemical is NOT metabolized and excreted, but rather bio-accumulates and continues to produce toxic effects well after exposure.

  6. #6
    Join Date
    Feb 2006
    Location
    Herrick, SD USA
    Posts
    4,043

    Default Re: The Case Against Imidicloprid

    Quote Originally Posted by grondeau View Post
    This is not a theory. All I was doing is fitting existing data to a convenient toxicity model and extrapolating to the age that bees normally live. The fact the the model works well with the neonics with other species, and fits published bee toxicity data, suggest that actually the chemical is NOT metabolized and excreted, but rather bio-accumulates and continues to produce toxic effects well after exposure.
    Then wouldnt you agree that a lack of residue could, among other things, mean either that there never was any residue? How could you differentiate without some sort of data? Again, I am not saying its not a viable theory just trying to understand how showing that something is possible may not be an indication of anything other than that it is, in fact, possible. Please clarify.
    "People will generally accept facts as truth only if the facts agree with what they already believe."- Andy Rooney

  7. #7
    Join Date
    Mar 2013
    Location
    Eugene, Oregon
    Posts
    14

    Default Re: The Case Against Imidicloprid

    Hi Jim,
    We CAN detect residue in pollen in plants grown from treated seed. Typical levels are in the 1-10 ppb range. Problem is, the bees dilute this since they bring in pollen from other sources as well. Plus the stuff does degrade. Our detection limit is around 1 ppb, so we are starting from a point close to the detecion limit anyway. By the time you dilute, you not expect to be able to detect it. This is not a mystery. Nor would you expect that toxins in the sub ppb range would kill bees immediately. There is not a lot of data on how low doses of neonics kill bees. Best paper is Suchiel 2001. There is nice data on how very low doses of neonics kill other arthropods (the other paper I ref.). Both sets of data fit the power law toxicity model very well. The model (and Suchiel's data) show individual bee mortality at sub ppb dose levels when given enough time. (7-10 dyas for Suchiel).

    Please tell me how bees that gather pollen from sources which have ~1ppb residue - could NOT have some residue more than 0.0001 ppb in their bee food. We can't see that, but it would be folly to assume that just those molecules jumped off the pollen load on the way back to the hive.

  8. #8
    Join Date
    Apr 2011
    Location
    Sacramento, Calif. USA
    Posts
    267

    Default Re: The Case Against Imidicloprid

    Quote Originally Posted by grondeau View Post
    If you are wondering why we don't see residue in collapsed colonies, the answer is that the effects happen at unobservably small chronic doses.
    In the USA we don't see a pattern of consistently more collapsed colonies in states where acreage of crops planted in crops grown from neonic treated seed is high (e.g. North and South Dakota) vs States where the acreage is low. So it stands to reason that if neonics were banned in the USA, the ongoing problem of 25% of the beekeepers losing 40-100% of their colonies each year would continue.

    Here's a 2012 University of California at Davis article downplaying the role of pesticides in bee health problems: http://www.universityofcalifornia.ed.../article/27351

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