My point has consistently been that I didn't personally note any difference in years I did vs. years I didn't use it and not that there isn't any scenario where it is beneficial. I invested in a microscope and was pretty diligent in pulling samples and trying to make treatment decisions based on the results. I finally decided that testing results are so fickle that it's hard to really make decisions based on what I was seeing. I have no doubt that there are some scenarios where it may well be beneficial, at least in the short term. My gut feeling is that if overwintering in a harsh climate there are probably more benefits to be gained. I did, though, years ago (pre varroa) run my own side by side on 500+ hives each treated and untreated within the same locations in central Minnesota and found my wintering success virtually identical. My recent evidence is about 3 years ago when, after receiving some test results from the state of South Dakota, I called to discuss the results with the state inspector Bob Reiners. He said I had some of the lowest reading in the state and wondered about my treatment regime. He was quite surprised when I told him that I hadn't treated and that I didn't have a clue why the readings were so low. There are plenty of other things to worry about when managing your bees, I finally decided not to make nosema one of them, that's my story and I'm stickin to it. It's also important to note, though, that nosema ceranae is a lot different creature and much more of a year round problem than nosema Apis.
