?Thank you Randy for taking the time to explain how you measure "sublethal effects".

From what you say, you do not consider a sublethal effect to be "colony collapse", although that's what you hinted at when you shared your impressions of one of the three neurotoxic-at-sublethal papers I listed (the de Almeida Rossi? one)  and the van der Sluij review.


I like the two main assessment measures you use:  colony size and colony weight.  Those make sense for all the reasons you listed.


I further agree with you that honey harvest success on canola in western Canada means neonics are probably not significantly harming bees on canola in western Canada.

But I cannot comfortably extrapolate, with you,  that this means bees are not suffering any effects from neonics on other crops in other places.


The plant species, the type of treatment cocktail, the nature of the soil, the behavior of the insects at different latitudes, the weather, the local forage, and many more variables mean that "one size" does not necessarily "fit all"....at least, not until we prove it does.


You are also measuring "field relevant dose" as the amount each bee brings to the hive, not the amount IN the hive.  So this means larvae, foragers, queens, and nurse bees are all potentially exposed to different levels of chems...but the ones considered "field relevant" are the forager levels.


So, we still need more information to explain differences in reported effects of neonics.

Enjoying this conversation.


Christina

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