1. Wintered bees die soon when new bees emerge in spring. Wintered bees do not forage honey yield.
2. The hive need masses new bees to be able to forage.
Foragers are over 3 weeks old. 3 weeks brood + 3 weeks as home workers
3. Different bees must bee in balance in the hive that it has capacity to nurse the home and forage
4. Wax building bees are in special age 2-4 weeks old.
5. Those bees which have nursed larvae in autumn, do not survive to winter.
6. After winter colony has lack of young feeding bees even if the colony is strong. Brooding explodes when new nursing bees emerge.
7. Lack of protein and other nutritiens shortens the life ow worker.
If you feed only sugar in spring buildup, to make larva milk the bees can take nutrities from their body but it shorten their life. Of course it depends if weather allow bees to forage pollen.
8. In late summer flowers stop blooming and they start to prepare themselve for the winter. When bees fly on landscape and do not get food, they die soon onto meadows.
The bee number of the hive collapses 70% in two weeks. So I may press the colony from 6 box into one or 2 box.