A recent Eawag study on freshwater invertebrates, shows how sensitive nature is to neonicotinoid levels considered safe:
"The slow starvation effect observed under constant exposure to low levels of neonicotinoids is not detected by conventional toxicity tests, as they are not carried out over a period of several weeks."
"Interestingly, pulses lasting no more than a day proved less harmful to the organisms than concentrations that were much lower but persisted for several days or weeks"
I can think of one bee which has a constant low level exposure to neonicotinoids over many years; The queen bee. Without strong healthy queens there are no bees, and yet science knows nothing about the effects of these exposures. Are we taking a big risk? - Of course we are.