Winter Bee
Lexikon
Winter bees are the workers reared in late summer and early autumn that carry the colony through the winter.
Winter bees are the workers reared in late summer and early autumn that carry the colony through the winter. They live many times longer than summer bees. While a summer bee reaches an age of about five weeks, a winter bee survives for several months.
The difference lies not in the genetic makeup but in physiology. Winter bees remain for a long time at the physiological stage of a freshly emerged summer bee. They have a well-developed fat body and a high content of vitellogenin, a protein that acts as a storage substance and as protection against oxidative stress. In spring they take on summer-bee tasks again, then age rapidly and die.
This is precisely why varroa treatment in late summer is so decisive. Bees that were parasitized by mites as pupae cannot build up sufficient protein and fat reserves. They emerge with too little vitellogenin and are unfit as winter bees. A colony can still look strong in autumn and yet collapse in January, because the winter bees were not physically able to cope.
From this follows the beekeeping rule to time treatment early enough that the winter bees already grow up in colonies with low mite loads, and not only once the mite burden becomes visible.