http://www.beekeeping.com/articles/us/gaucho/manifestation_paris_us.htmFrom Dems will win article
midacloprid has a negative effect on individual bee behaviour,
at 1.5 ppb when foraging
between 6 and 12 ppb. when relating to criteria allied with olfactory memory and recruitment
When relating to sub-chronic toxicity and daily doses of 4.5 picog.,
THERE IS A SIGNIFICANT IMPACT ON THE SURVIVAL OF THE HARVESTING BEES.
Due to sub-lethal effects of certain metabolites of Imidacloprid to be more toxic than the original molecule
Due to Imidacloprid being available through nectar and/or pollen of crops treated with GAUCHO at a level of up to 5ppb
As the level of accumulated residual Imidacloprid from 3 previously GAUCHO treated crops (equivalent to that delivered by a sowing of GAUCHO treated sunflower seed)
That sunflowers and maize are particularly capable at absorbing residual Imidacloprid
IT IS EVIDENT THAT DURING THE FLOWERING PERIOD OF GAUCHO TREATED SUNFLOWER AND MAIZE AS WELL AS ALL CROPS WITH APICAL INTEREST CONTAMINATED BY PREVIOUS GAUCHO TREATMENTS - FORAGING BEES ARE EFFECTIVELY EXPOSED TO DOSES OF IMIDACLOPRID WHICH IN LABORATORIES HAVE REVEALED A NEGATIVE IMPACT.
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So there is evidence just nobody wants to say it on TV