I found another great video by Barnyard Bees about mite control in Bee hives. I think this approach would work great on our Bonsai trees as well. It looks very interesting to me. They say its about 100% effective in the fall and then once a month touch up. I could see doing this during our growing season. Colorado has lots of mites due to the dry nature of our region. I have posted this video under Diseases/Insects page, under Bonsai Basics.