Andy: Interesting observations - give me one more field season and I will tell you whether our field trials support your viewpoint. So far, I find that I differ with most mite reseachers in that our research and model both suggest that mite numbers oscillate like a roller-coaster. In addition, when the mite numbers in untreated hives peak, down goes the colony. However, this may be a chicken-egg issue. Did the mites increase and as such contribute to the loss of the bees, or was the colony failing and as such were predisposed to mites?? Don't know. What I do know is that I would not spend much time trying to put the last decimel point on how many mites are in the hive or how many bees infested - 1 the numbers can change dramatically from day to day, 2 colonies with lots of mites suddenly turn up without mites, while colonies with few mites suddenly get over-run. The counting portions of our model suggest that there is a very dynamic interaction going on between mites and bees. The development time of the two is that when they are out of synchrony, things slow down and the bees more or less dilute the mites out. If they get in synchrony, the mites can quickly outpace the bees. Jerry Bromenshenk P.S. What software do you use to run your B.B.S. and what kind of computer are you running it on?? P.P.S. I will be very interested to see what kind of response your message gets from the List. [log in to unmask]