> I wonder what inspired this group to stick their collective neck out while the jury is still out.  Doing so seems to me to be unnecessary and somewhat suicidal -- unless I am missing something.

The report is nearly forty pages and I can't pass it on. However, some salient points:

> Normally, the results of manipulative experiments are the hard currency of decisions about causality in natural science. In situations involving public concern over environmental change, however, decisions about causes sometimes must be made under political pressure despite scientific uncertainties, which may include the lack of experimental evidence.

> We propose to evaluate whether neonicotinoid pesticides cause population declines in honey bees without having recourse to decisive experiments. Specifically, we employ "Hill’s causality criteria" as a structured process for making an expert scientific judgement that is open to critical inspection and repeatable by others.

> Our goal has been to assign certainty scores to each of the criteria to reflect the degree to which available evidence supports the hypothesis that neonicotinoids cause honey bee declines.

> In summary, experimental evidence to date has not demonstrated that trace dietary imidacloprid causes population decline, but neither has the testing been stringent enough under environmentally-relevant conditions to reject this causal hypothesis convincingly because of shortcomings in statistical power.  

* * *

comment:

These days we hear a lot about the "precautionary principle" which proposes that in the absence of empirical proof of safety, and in the presence of suspected harm, one should hesitate to approve a potentially dangerous practice. This of course, would preclude most of what people do. We have to make judgements based upon incomplete evidence, and fear of harm is not sufficient to deny, for example, permission to use pest control products. If a practice is judged to be safe based upon a reasonable amount of testing, then one moves forward. We cannot have 100 years of data prior to making a decision which, 100 years from now we may regret. 

What these authors do is to counter the claim that neonics "may cause harm" with a large body of evidence which appears to show that while they may, there is insufficient evidence at this time to show that they do. If there is a preponderance of evidence to support the claim that these products *Do Not* cause honeybee decline, then there is little justification to outlaw or reject them, and the causes of the decline should presumably be looked for elsewhere. This is certainly not the only plausible factor that could cause declines. Many species are declining throughout the globe. 

Overcrowding, transfer of exotic species from one region to another, viral evolution, pest resistance to interventions, all of these could and no doubt do contribute to the decline of bees in certain regions. All the same, one must bear in mind that bees are not declining everywhere, and there is no clear evidence that the current declines even approach critical levels. The supply of bees for pollination has proved to be adequate when growers offer sufficient rewards. Prices for honey are high and there are adequate control measures to keep varroa, etc. in check. Whether this is "sustainable" is another matter. 

PLB

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