...I got the impression the bees have priorities. A split has to become an established colony and might lean all actions towards breeding and storing, ...
Exactly where my thinking led me -The 1st goal of the [new] hive is Brood, Stores, and Survival. After that might come disease prevention, and replication (swarming) ... I.E. They shift over to their long-term goals once all short-term needs have been met, and Mite resistant traits begin to show up more. ... This is what I think I might have seen as the difference in Hives. ... but it's just a Hypothesis right now.
I monitored mite drop for weeks every day after my bees swarmed and after making splits.
The mite drop differed very much between colonies ( I have 11 monitored), it differed before and afterwards. I correlated the drop to bee numbers.
Before I always thought the bees would breed fast away and the mites were left behind but it?s not true. Very fast the drop numbers were the same as before, but differed because of IMO genetics.
The swarms mite infestation rose quickly to a high level and I had crawlers. But some weeks later the hive was established and mite numbers were as before with the mated queen.
We made 4 splits out of my best queen this year in spring. I got the old queen and a daughter, a co-worker got two daughters.
Every split had two broodcombs dadant size. I restricted mine to 5 combs, hanged two honey combs and fed. After 4 weeks I expanded to 8 combs and later to 12 combs. They were filling the box.
My co-worker practises "live and let die" and did not feed. He had comb but only one honey comb. We had a drought. His colonies never thrived.
One died of mites in late summer and the other was robbed by a strong neighbor because it had no defense. Both starved.
Well, to learn about bees and to care for them in a man made stress situation is important.
He might tell people the bees were not resistant but it?s was failure of management which killed them.