Hello Karen & All,
I removed a swarm from a building a year ago. I posted the removal on bee-L.
The owner swore the bees had been in the building four years. I am using
those bees for drones for the first batch of SMR queens. I must caution all
beekeepers that it is almost impossible to verify how long the bees have
went untreated. Hives die from varroa and new swarms arrive without many
owners (not beekeepers) noticing. I was leary of my swarm and said so in my
post last year because I found both black and yellow bees. A year later I am
still seeing both black & yellow bees in the hive. They are carrying a very
low mite load for this time of year. Much lower than my production hives so
maybe they are survivors. Good luck with yours Karen!
Bob