Regarding the number of replications, at the Dyce Lab we ran numerous studies to see the effect of this, that, or the other. We always had large numbers of replications, half of which were control hives. 30-60 or more hives was the usual. I remember several seasons of testing screened bottom boards: we weighed the hives, counted brood frames, winter survival, all of it. In the end there was no discernible difference, which we took to mean that screened bottoms don't do anything one way or the other. 

Then one day I thought: what if the effect has been masked by drifting? We usually had the hives in pairs, two meters apart, but knowing bees this may not have been nearly enough to prevent wholesale drifting. I suggested to the PI that we should set up two apiaries about 100 yards apart. He said that would invalidate the results because of "the apiary effect." Frankly, I think putting two small apiaries in the same field but separated by enough space to exclude drifting would be a good plan. 

PLB

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