A lot of the studies in the US showed the largest chemical contaminants in the wax was fluvalinate and camophous. Beekeeper chemicals for varroa control.
Pyrethroids in this study seem to be just as likely a cause.
It is understandable, that fluvalinate and coumaphos are found at high levels in hives, as that's where they are applied.
However, the toxicity of neonics is thousands of times higher than of those other chemicals, and they can affect colonies at doses that can hardly be detected in hives.
I used pyrethroids on my bees against varroa, and there was no observable problem at all, they were thriving.
Originally it was blamed on cell towers and radio waves.We need to stay tuned.
http://www.beeccdcap.uga.edu/documents/CAPArticle16.html
The link doesn't work.
The story about the cell towers was a red herring and meant to confuse the issue.
I am not a fan of these towers, but they are clearly not linked to the mass colony deaths at the moment.
Stress on the colonies is also a contributing factor. Migratory keepers lose as a percentage ,more bees than the hobbiest to the symptoms of ccd.These colonies never get a rest period,being trucked from one end of the nation to the other, constant feeding to keep brood rearing going and most likely a steady diet of fumagillin and anti varroa treatments.They have to do what is necessary to keep these bees alive as dead bees do not make money.
Stress is not good for bees, but migratory beekeeping has not changed drastically during the time when CCD appeared.
What changed was that Clothianidin, one of the new neocis, was introduced to the states.
Clothianidin is several times more toxic to bees than Imidacloprid.
Most hobbiests bees die in the hive. Not a ccd symptom. Most likely beekeeper error.
I read more and more reports of hobby beekeepers where their colonies have suddenly dwindled away in winter, especially from the US but also from Europe. This is typical for CCD.
And if you do a little looking there have been reports of fall dwindling for a long time.Not a completely new problem,but when it hits guys with a couple thousand hives it gets a lot more attention than when a backyard keeper loses 50 percent of his hives(which may be just one of two).
Fall dwindling could be down to varroa or problems with the queen, but in both cases the reason for the dwindling can easily be identified.
With CCD, the majority of the bees leaves within a short period during late autumn/winter.
It was made quite clear by those who examined CCD hives, that
they had never seen anything like it before.
If you do away with the neonics, I doubt all instances will disappear. In Finland they kill varroa with oxalic acid rather than fluvalinate and camophous.This does not leave residual in the comb.
In France neonics were banned from flowering crops and the major bee deaths stopped.
If the neonics cause this, how do we explain the hives that thrive despite the exposure? I'm guessing they had at least one less stress factor.
I take these stories of hives thriving next to neonic fields with a lot of caution.
Maybe, if it's just Imidacloprid used on OSR then the colonies can get over the exposure during the summer months, only showing some queen failures and increased susceptibility to varroa and nosema.
But colonies exposed to Clothianidin from maize/corn at midsummer will often succumb to CCD in late autumn/winter.
I have seen a whole apiary of ten hives dead, they had access to clothianidin treated corn for the first time in the summer before.
Nothing else had changed, no heavy varroa, no migration. Everything looked perfect, strong colonies with young queens.
By midwinter the hives were empty of bees, with tiny clusters including the queen left behind, and plenty of stores untouched.
:(
