A while back there was a question about the use of old beekeeping
     eqipment and the liklihood of infection of the new colony by varroa -
     to which I posted a reply.
 
     Talking this weekend with Stephen Martin of the National Bee Unit here
     in the UK, (who is doing some neat work on varroa biology), he has
     recently had some experience of transferring some old dis-infested
     brood combs into new colonies (which had previously received a
     miticidal treatment) and which were subsequently given a clear bill of
     health.
 
     However, a few days after introduction of the old combs into the new
     active colonies, he recorded a mite fall - not a great one, up to
     10/12 mites, all dead. This was apparently due to the bees cleaning
     out the cells of all debris left behind by the previous occupants.
 
     The timing of the mite fall seems to vary but should show up within
     2-3 weeks of old comb introduction in an active colony.
 
     It just goes to show how easy it can be to misinterpret a mite fall
     sometimes; this doesn't represent a new infestation, it's just good
     housekeeping by the colony. Sudden surges in mite fall before, during
     or after a miticidal treatment may be partly attributed to this
     factor.
 
     Just thought this would be of interest to the group.
 
 
 
     Max