Ian Watson wrote:
> >Replacing the strips with new strips (with the 99% killing power) will not
> >encourage build up of tolerance!  Leaving in old strips with a reduced
> >killing power will!
>
> That may be true.  I'm not an expert, and would be interested in an in-depth
> explanation of the mechanics of resistance by some of our more knowledgeable
> members.  It just seems to me that continuing with new or old strips after the
> proper time would kill off only Apistan-affected mites and leave lots of room
> for the Apistan-tolerant ones to fill in the vacant "space".
 
 
        The 1st paragragh is correct. It is important to get as near a 100%
kill as possible thereby leaving very few survivers. It may seem that
the few survivers would quickly establish a "super" population of
resistant mites, and that is somewhat true, but remember that there are
other sources of mites that contribute to the population. I'm refering
to the mites that are aways migrating into kept colonies from the feral
population. Of course this factor is variable because the size of the
feral population fluctuates, especially since varroa.