This is a topic that could have tremendous importance (re. pollination) as the "varroa resistance to miticides" story unfolds. I'd like to hear of any experiences with the "Yugo" or other potentially resistant bee stock. In B.C. this year, we monitored the first year (or so) of varroa population buildup, and did trials to develop recommendations for control. In measuring the varroa populations, it seemed that some colonies consistently produced many more mites , than others (even after mite levels were reduced by treatment). There are a lot of possible factors that influence the mites/bees, and 2 colonies with an uncertain past are not much to start from, even though there may be a large difference in mite numbers. Some of the proposed mechanisms of resistance to varroa seem difficult to easily measure (juvenile hormone titer, post-capping period). However, the grooming/removal of mites could be a major mechanism, and one that might be easily compared between colonies (proportion of mites with damage). Are any of you working on something like that? Kerry Clark, Apiculture Specialist B.C. Ministry of Agriculture 1201 103 Ave Dawson Creek B.C. V1G 4J2 CANADA Tel (604) 784-2225 fax (604) 784-2299 INTERNET [log in to unmask]