Dave Black wrote: > Would anyone agree that this (surviving untreated) is not the criterion > for success. Surely we would want to monitor the mite population. How > could this be estimated without using a chemical knockdown and stopping > the trial ? I would agree that colonies surviving and remaining healthy is exactly the criterion for success. In the process of developing such bees monitoring representative colonies would be needed. But, that is only for the purpose of study. Beekeepers only want healthy colonies. Tom Elliott