I've searched in vain for it - somewhere there is a list of approved "icides" for use on beet crops - it runs into hundreds, including at the top of the list, neonicotinoids, and a large number of fungicides (which have been shown to make the "Nns" a thousand times more toxic for bees)
Then there's the claim that beet sugar is "pure" and totally free of "icide" contaminants, which is just plain wrong and untrue - there are certain limits of contamination which ARE allowed, usually weaselled as insignificant levels - it would be virtually impossible to remove all the contaminants from a crop so liberally "blanket bombed" throughout it's life, so they rely on "safe levels" (usually decided upon by the industry itself)
So to be honest, you're probably best to seek out organic sugar to be 100% sure of it's intrinsic safety, but I've so far been pragmatic and taken the advice of the "natural beekeepers" who seem to be of the opinion that of the two forms of readily available sugar, cane is best.
As to the claims of feeding bees with beet sugar which have apparently survived and thrived, I don't doubt it - it's not like a lethal dose of cyanide which renders the victim stone dead swiftly, but often poisons act cumulatively and synergistically over a long period of time, and may possibly be one of the myriad causes of bee losses (the bees get weakened by one thing, and succumb to another, which they would have "thrown off" naturally)
I prefer to err on the side of caution where "chemicals" are concerned - as I said in my original post, I was giving my
personal view, which is held by many other beekeepers - as I also said, there's many opinions on this as there is in all matters of beekeeping, and I was merely redressing the balance of the rather frightening "it's fine" claim -I'd sooner go with the more honest "I don't KNOW, but will proceed with caution" view..........
I've got my own way of avoiding the question altogether, I try never to feed
sugar, but would sooner leave them their own stores..........