Jim, Referring to your reasonings for comb rotation. Presuming that your levels of AFB presence are correct, you suggest that rotation will in your case have a 1 in 5 chance of removing an "infected frame" in any one year. Do you not agree that a bee colony from which you would have removed the potentially contaminated frame would also after removal of said frame still contain 9 other potentially spore contaminated frames! i.e. what benefit would be derived by the removal of only one frame from a AFB contaminated colony? Sequential frame removal would only be useful if AFB took 5 years to reach a level that resulted in detrimental consequences on the population. Plus, if the removal of frames was undertaken sequentially as frame contamination took place. If you agree that this not to be the case - then surely random removal of frames from an AFB infected colony will have equivalent consequences and potential benefits as those of sequential frame removal. Hence that practice of removing all frames etc. from an "infected colony" and only replacing them once the hive body et al. has been well toasted with an efficient flame throwing like device. Regards, Peter :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: -- Visit www.honeybeeworld.com/BEE-L for rules, FAQ and other info --- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::