Hi Joe, I understand the limitations of mite drop counts. However, in this study, the only measured variable was mite drop. So why measure it if you're going to discount it? A higher mite drop every year for four years in a row means more mites. What some seem to be missing is that the author counted mite drops while he treated with Apistan. Unfortunately, he didn't count for a full brood cycle, which would have gotten most of the mites in the colony. His counts weren't an illustration of the bees cleaning out the mites due to small cell--it was an approximate measure of the mite infestation level at the end of the season! Clearly, in this study his small cell colonies built up more mites each year. However, upon looking at the data again, the 2006 counts do imply that small cell may have suppressed mite buildup somewhat. Even though there were more mites in the SC colonies, they hadn't received an apistan treatment the year before. Again, I'm not discounting an effect due to small cell, but this study doesn't really tell us much, other than that his SC group had higher mite levels each time he dropped the phoretic mites off with Apistan. >This lengthening of the phoretic period, (arguably the highest risk period >for varroa) Data by Martin and others would not support this. Phoretic varroa have very low mortality. Mites emerging with bees have extremely high mortality. > Relying on mite counts alone IMHO is a failure to properly assess a colony, which is of course (as we all know) should be based on ’over all performance’. The point I'd like to make is that the bees that can tolerate mites (Apis cerana and the Africans) rarely allow the mite level to exceed a 2% infestation on the adult bees. So depending upon the type of mite counts one makes (see my article in ABJ on comparison of various sampling methods), or at randyoliver.com), this level does have significance. Colonies with very high mite levels are time bombs waiting for viruses to explode. And Dee, I do understand about high mite drops in Sept being normal--I made that clear in my article on mite population dynamics. However, in this experiment, the drops were not natural, they were accelerated by Apistan. > culling colonies based on mite drop could perhaps be a selection against > two of the known mechanisms for mite resistance; grooming behavior and brood attractiveness. I suggest that selection of breeder queens be made on performance first, and mite level second. By mite level, I don't necessarily mean natural mite drop, unless you know how to interpret mite drop based upon seasonality. Far better to use accelerated mite drop with powdered sugar or oxalic, about mid August, in order to find which colonies allowed the smallest mite build up during the season, by whatever mechanisms. By the way, did I ever tell you that I measured the cell sizes of the last feral that I picked up? They ranged from 4.7 to 5.4 for worker cells. The pupae in the smaller cells looked tiny! Randy Oliver ****************************************************** * Full guidelines for BEE-L posting are at: * * http://www.honeybeeworld.com/bee-l/guidelines.htm * ******************************************************