My 2 cents on Russians vs. Italians In Oklahoma
I have 5 hives and 3 are currently Russians. I'm also in Oklahoma, so we have the same heat. Last year I started with 2 Russian hives.
I do think that Russians shut down more when it gets hot. However, I do not think that it is the heat. Instead, I think that when there is a dearth, the Russian queens simply stop laying eggs. They also overwinter on a MUCH smaller cluster than Italians. However, that's not all that bad, given that there probably is not much nectar to be had in Oklahoma in August. Even in wet conditions like we've been having, its still hot and dry in August.
Their frugalness is both good and bad. They use less stores when times are tough, and they overwinter better for that reason. Also, I think that even if Russians produce less honey on average, the beekeeper could rob them harder and it would be a wash. Based on my hives last year, I think that Russians probably can overwinter on a single deep in Oklahoma, particularly if you feed them a little in Feb. They would certainly do fine with a deep and medium over winter.
Based on last year's experience, my main gripe with Russians is that they were slow to build comb. However, the Russians I got this year (3 hives) did not have that problem and have drawn comb just fine.
My other concern about Russians is that they do not take full advantage of early nectar flows. I have one hive that is right in the middle of Tulsa, at my house. At that location, there is lots of nectar to be had in March-April, due to many fruit trees and early blooming plants that people have in town. I think I could have a booming Italian hive by mid-April. Based on my experience, my Russian hives probably do not catch up to Italians until about May 1. It could be that Italians are better for honey production if you have an early flow. If you are in a rural location in Oklahoma, June is probably your primary flow, and I doubt Italians have any advantage. If you happen to have a lot of early nectar sources, I think you may miss out on some honey with Russians, simply because they don't yet have a sufficient population. In other words, Russians don't get out of the brood rearing mode and into the honey storing mode until later in the year.
I personally now have 3 russian hives, one Italian hive and one hive that is from a swarm where the bees are dark. I intended to requeen the feral hive with an Italian queen because we have a love-hate relatinhship (they love to sting me and I hate them). It is in a yard where I want to compare Russian and Italians, and I will be happy to share what learn if I ever get that far.
ndvan