Hi Brosville
Nice to see some calm, thoughtful comments from you!
Since you didn't answer my question, maybe I can direct you to some recent research involving Maryann Frazier of Penn State which you can read on the web:
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0009754
Thanks Pete, I hadn't seen that one until now!
You can see LD50s, and the percentages of detections of things like imidacloprid and all the other pesticides in wax, pollen and bees. Now look at the beekeeper-applied chemicals and their LD50s (and bear in mind that some of them also can show synergistic effects with particular fungicides).
Note I'm not saying that this is good - it is a shocking indictment of the pesticides used particularly in US beekeeping and also in US agriculture. Our use of things like imidacloprid in agriculture is a lot more controlled, and implying that our regulators are lax is just simply untrue. But none of this backs up those complaining about neonicotinoids.
Now then, your Maryann Frazier document. It is three years old, and three years ago *I* thought that CCD was likely to have a major pesticide component, particularly neonicotinoids. Clearly she did too.
Here is a Penn State paper from one year ago, and Maryann Frazier is an author on this too:
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006481
Here are the principal findings:
'Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels), no single measure emerged as a most-likely cause of CCD. Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor) were higher in control colonies than CCD-affected colonies.'
Read the whole thing if you don't believe me.
There are several other recent 'multifactorial' studies on colony losses, and I'm not aware of one that shows any sign of a link to pesticides. OK, I agree that pesticides in gardens shouldn't be enthusiastically encouraged, but if you are going to campaign against something you do have to have at least some basis in reality surely? Or is it all OK just because a German multinational company is behind your most detested insecticides?
If all of this is too technical .... and your bees use oilseed rape, the biggest single source of imidacloprid for UK bees ... just ask yourself how did they look last May when the rape was out? Confused, disorientated, declining, or building up rapidly and storing a surplus? And the wintering bees that were raised in August/September and which everyone worries about overwinter, what were they raised on?
best wishes
Gavin