Hi Barry! I just visited the web site you suggested and I can learn a lot there. As for the over kill, I ment that when all said and done, I was going to alternate , eg. formic in the spring and apistan in the fall and it would be only if need be. Probably by doing drone trapping method I would only have to do the fall treatment. I am in a very bad area for varroa mite, and we are just new to the situation and how to treat it. I never knew about varroa untill this year. Thank You, and I need all the help from expereinced beekeepers I can get! Debbie