Thanks Alex, interesting comments. Here are some more of mine:

Almost any biological effect of a compound increases with increased exposure time. There is nothing special about this. As I indicated before, imidacloprid does *not* bind irreversibly to acetylcholine receptors according to the literature, which makes his comparisons to carcinogens entirely spurious.

The declines in biodiversity are huge issues and, as Alex pointed out, complex. Man is stressing the natural environment in many different ways. Pesticides could easily be part of that, but if we are to understand that it requires high quality unbiased science. It seems to me that Dr Tennekes has come to a personal conclusion that he knows the main reason for the losses he so rightly deplores, and is trying to marshal arguments that support that case. If what he does obscures the fact that the real reasons are complex and multifactorial, then he is doing everyone a disservice.

Log-log plots. These are common devices to get straight lines out of biological data. I use them myself for other topics. There is no link to the action of carcinogens from that analysis.

Ground water concerns: absolutely! There were concerns expressed in the US about groundwater contamination by imidacloprid, in New York I think. I remember commenting on them on Bee-L. Regulators that allow uses of toxins at such a rate as to contaminate their environment so completely are failing in their duty of care. You just shouldn't be allowed to use such compounds on such a scale on golf courses or whatever was contaminating groundwater in the US and in the Netherlands, in commercial bulb farming or potato growing or wherever the contamination is coming from.

Surface water in the Netherlands. Why is Dr Tennekes citing 5,000 times the MTR in some samples - is that real? The map is scary enough, but that only shows 'over five times' the MTR. The MTR is 13 ppb, so is already close to the level which could harm wildlife, and five times that level indicates a serious problem that needs sorting right now!

So my interpretation of this is that there sounds like there is a real underlying problem, maybe a really serious one, but unfortunately Dr Tennekes' intervention is not helping. Blow the whistle by all means, but don't do it by misunderstanding the issue and invoking spurious arguments.