And how have the bees overwintered????
How would I know? I am not going into the colonies to find out just yet!
Simple fact is that a strong colony can survive outside, no particular problem to them.
Mary in Warwickshire had a colony in the corner of the window brickwork and that survived the snow in 2010. I think it may have finally succumbed to wasp attack last summer, but I am not sure.
I do know, from past experience, that insulation pays dividends. I know that insulated sides on my Dartingtons lead to brood right up to the side walls (as long as it does not slip down, as it did on one side of one Dartington last year, leading to a very lop-sided brood nest in spring).
A sheet of EPS under the roof costs less than a quid. It only needs to save a kilo of stores to be well ahead (my hives usually over-winter on honey stores). My colonies have not needed to be fed fondant this winter at all.
Go figure. Finman needs insulation for his bees to survive. He knows that with open OMFs the bees consume far more stores. I don't wonder why; you might. None of my hives have been damp in the last 8 years. Go figure.
I could weigh hives and compare winter weight loss, but I don't. I don't have enough hives to get a certain result that is reliable. I don't need to. Common sense tells me that it is a fact that insulation has a payback far in excess of cost. I have overwintered small colonies that would almost certainly have perished in an uninsulated hive. I also know that the greatest heat losses in a house are through an uninsulated roof. I know that it is damp conditions which are more likely to lead to over-winter losses. My bees over-winter very well usually.
But actually quantifying the differences at the beginning of a cold March is a laugh, a mug's game.
Some may just be happy that the colony has survived this far. That is not a measure of whether insulation should be used or not.
RAB
