Oxalic acid is not very toxic. I've read it slows down the bees for a few days, but I've not seen any impact on population. You get oxalic acid in a rhubarb pie

Oxalic acid is not very toxic. I've read it slows down the bees for a few days, but I've not seen any impact on population. You get oxalic acid in a rhubarb pie and it is harmless. Bees get a very weak solution dribbled on the top of the frames for tens of thousands of bees. They don't get much at all. As far as pesticides, I am sure they harm bees, but CCD has pretty much gone since the aggressive treatment of varroa started. Russian bees are thought to have brought varroa with them. Before that there were pesticides and most were much more toxic including DDT but the bees were just fine.