Hey BlueBee. I was googling like mad on this so here I am. My question is whether insulation lengthens the fall brood-rearing season to a dangerous extent. ie costs you more in honey (and pollen) than it saves. Do you have a handle on that?
I know that it does not. Old queens stop brooding 2 weeks earlier than this summer queens.
Hives stops brooding when they do not get any more pollen from nature, or nectar. Small brooding starts again when I give winter feeding.
It depends much on pastures.
Then stop brooding depends on bee strain, how it is adapted to local climate.
What ever the weathers are - or insulation-, plants prepare themselves for winter and stops flowering. That tells to bees too that autumn is coming. Or in dry weather, bees stop brood rearing when dearth stop blooming. African bee moves to another district to avoid short of food.
If hives do not react on short of food, they will die.
They will die too, if they continue brood rearing and new bees have no wintering ability. (lack of pollen in the hive)
I bought 4 queens from Cyprus 3 years ago and they react on late summer just like local bees. But they are mad to start brood rearing in spring too early. Cyprus is near Africa.