I had Russians as well. They are a funny bees to me. Hard to re queen. Want to make their own. Been discussed before. I had a couple of Russian hives that were "mixed" with local that re queened themselves. I finally let them have their way. I think the stock was good and they contributed to the overall gene pool. The two I have left are quit the mix of dark and light bees. It actually seems to fluctuate. More light bees in the summer and more dark bees now. Just speculation. I guess my point is the Russians(any strain ?) seem to get assimilated and perhaps exhibit a collective collage of the genes in the area unless pure strain is put back in. Just thinking out loud.
Interesting study that seems to fit into this discussion.
Julysun elevation 23 feet. 4 Hives, 2 years.