Environmentalists say that CCD is caused by neonicotinoid pesticides. They point to a study that comes to this conclusion, and they have a friend in the mainstream media, which is highly sympathetic to their anti-pesticides bias.
But is there really a consensus that neonicotinoids cause CCD, or even pesticides of any kind? Leading scientists don’t even mention neonicotinoids in this article from PLOS ONE. In fact, they found that the acaricide coumophos was found in larger concentrations in control apiaries in the study as opposed to apiaries that were affected by CCD.
The reason, they theorize, is that coumophos, which is the active ingredient in mite-control formulas, is present in larger amounts in apiaries where beekeepers are more diligent in taking care of their hives.
Coumaphos is a product used by beekeepers to control varroa mites. Elevated levels of this product in control apiaries suggest that beekeepers managing those apiaries had more aggressively controlled for this parasitic mite than beekeepers managing CCD apiaries. In addition, control apiaries tended to have higher levels of fluvalinate (P = 0.06), another approved acaricide, the authors state.
This doesn’t mean that coumophos is preventing CCD in colonies, nor does it mean that varroa mite infestation is causing CCD, they add. They note that there was no difference in mite levels between CCD affected apiaries and control apiaries in their study. But this, too, does not necessarily mean that varroa mite infestations don’t play a role in the occurrence of CCD, since there could be a residual effect from mites that wasn’t detected in the study.
They don’t draw any conclusions from the study, but they seem to believe they are zeroing in the mechanisms of how CCD occurs in honey bee populations. Neonicotinoids are not even mentioned as a possible factor.
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