Hello All.
     All this recent talk about varroa floors/traps and all got
me thinking - a dangerous thing.
 
The recomended method of testing varroa infestations (USA) is to
install a varroa trap, and insert Apistan strips.  Then 24 hours
later, pull out the trap - do the count - and determine if the
levels are sufficient for treating.  If the levels are low, the
strips are pulled out of the hive, otherwise the strips are left
in.
 
Here comes my Question...
Could the repeated testing for varroa lead to breeding resistant
mites???   In the one day that the strips are in the hive, the
easily suseptible mites are killed, but the ones that remain are
a little tougher and were not killed.  These tougher mites then
continue to breed until the next test.  Given the fact that the
overall mite populations are low, and the easily killed mites are
removed, this would result in a higher percentage of mites that
were not initially affected by the apistan.  Over the course of a
year or two, you might have a hive full of mites, but a the test
will not reveal the true populations because the mites are not
killed by the apistan within 24 hours.
 
Any  thoughts on this from the bug and chemical people out
there!!
 
Rod Billett
Lexington, South Carolina  USA