OK, so I've been treatment free for a while and its becoming apparent that something needs to change. Most of my hives get through the first year, but in the second year they die out. Example - I had six hives this year. Two of them were survivors from last year and four of them are new this year. This fall the two year old hives collapsed. One week they are full of bees and looking healthy a week or two later they are gone, with very few dead in the hive. (This happened in late October in Oregon where the temps have been freezing at night)
Both of the two year old hives were from "survivor" stock. One was a nuk purchased at Old Sol and the other was a split from a local hive that has been around for a number of years. I simply cannot get a hive into year three, no matter how what I do. The hives had excellent stores and I even fed pollen patties (from Mann Lake) just to help out. (first time I have done that)
I have no doubt the bees are leaving because of high mite loads but since I don't treat with chemicals I'm not sure what I can do. My hives are made up of a mixture of small cell boards and foundationless frames.
Open to suggestions as I'm very near going back to treating my bees with a miticide.