I have heard conflicting reports as to how long to leave strips in the hives. Some say 30-45 days, some say 60 (and no more). I think that the label states 59(?) days [I don't have a label in front of me so DON'T take that as any direction.] If the mites life cycle is approximately the same as worker brood (21 days). [I think I read that somewhere], then leaving strips in the hive for 30-45 days would kill 1-2 generations of female mites leaving the cells, 60 days would kill 3 generations. This does not consider those freeranging mites that are coming into the hive from outdoors. I have heard of different Apistran strategies: Some state place apistran in the spring for 60 days prior to supering and again for 60 days after harvest. Some state place apistran only once, on July 1, then remove on 1 Aug and place supers for fall flow [Approximately 30 days]. Some state place apistran once, for 60 days beginning the middle of August. Ok, folks. What is the story here? What strategies have worked for you. My own experience in Dayton, OH has been that if I wait until September to treat, its too late -- the bees are goners unless something else happens. Last year I placed strips into my two hives on Aug 6 and left them for 60 days last fall and then again on Feb 6 and removed them 49 days later. So far both hives came through strong, healthy and ready to go. This is the first time I have successfully overwintered my hives after 4 years of trying. Pulled drone brood revealed no mites to date. So I am trying to scope out my plan for this year. I don't like putting strips in at all, but must. Howeer I would like to minimize their use as much as possible. Would a stragegy of placing strips from between nectar flows for a period of 30 days provide enough coverage to protect the bees? Mark Egloff [log in to unmask]