"This is a curious citation to choose. As i understand it, IMI does NOT block receptors--instead it opens the sodium gate. It is therefore an agonist, not an antagonist."

Anything that interferes with receptor function can be called a "block". You can block a door closed, or you can block it open. Same idea. A block can hold a channel open or hold it closed. Either way, it's not working properly....it is "blocked". Yes, it is an agonist because IMI blocks the channel in the "open" position, causing the neurons to depolarize and stay depolarized.

Yes, I am saying that metabolism of neonics is not happening inside the synapse and that compounds have to diffuse out in order to be broken down, unless they can be inactivated by native neurotransmitter degradation enzymes like acetylcholinesterase. I do not have any reference that shows otherwise. Acetylcholinesterase cannot degrade IMI.

Back to what I said earlier....does it matter? Some of the metabolites of IMI take 10 days or more to clear (Suchail). That is most of the lifespan of a field worker bee. Studies show that neonics plus Nosema are worse than either one alone. Neonics plus fungicides are worse than either one alone. Neonics have different toxicities to different castes of bees. Neonics and poor forage are worse, etc, etc.

I think it matters because we should be learning how to better tailor treatments to the local conditions. We should start by looking at the Nosema/neonic problem and see what can be done there...how are the bees affected, and specifically: why is the combination of Nosema and neonic more lethal than either one alone? We need to better understand the lethality of fungicides and whether the application methods of fungicides and neonics can be tweaked so that they don't produce a double whammy to the bees.  (For instance, my understanding is that most fungicides interfere with eukaryotic metabolism. This makes it likely that a neonic would last longer in a bee that isn't properly metabolizing...but somebody should prove this!)


We need to keep learning and we should start by asking the right questions....to me this means neonics must stay on the table, not be dismissed as "safe when properly applied". They remain part of the environmental picture experienced by the bees, and possibly part of the problem that compromises productivity and survival.


Christina

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