,

"I've been monitoring a couple hundred test hives all summer, allowing them to maintain varroa counts (mites per 1/2 cup of bees, 100% recovery) in the
20-50 range and up. Colonies with mite counts up to 10 appear to be
relatively healthy and productive"



Well at first thought,  that confirms my thought that Jeniffers number was a bit shall we say optimistic.  Generally I have been very happy with that kind of number  1-2% in Aug

BUT




"The above are for mid- to late-summer counts.  Data from Germany indicate that success at winter survival drops strongly at over 1000 mites/colony going into winter.  As the colony approaches fall, at some point it begins to restrict or cease broodrearing (in cold-winter areas).  At that point, all mites are forced into phoresy, so it's then easy to figure the total varroa population in the hive."


When I take this tidbit and do some math.....  lets say the average population is 30k in aug  with a  1% infestation I have 300 mites.  BUT  if 2/3 of them are under cappings,  my real number is now 900,  one quick cycle and I am well over that 1000 mite mark add to that when my hive starts to contract to the 20k number  I would bet  money most of the mites are on younger bees and not lost.    This would lend credence to the concept that 1% is too high.



Which makes me continue the thought,  where is the damage from those 1000 mites?  If your correct Randy,  and the higher numbers are "okay" that flies in opposition to the numbers From Germany.  Is it possible that the higher numbers are not a problem with high summer turnover,  but a big problem for winter bees?  

My goal to date has been get winter bees bred with numbers under 3%  and then clean up in NOV with OA, but of course this is after the brood is already reared.  In the past this has done well for me,   but I am pondering if I can do better for winter bees.


Charles

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