Hello Everyone,
 
Well, it looks like the cold weather is finally here to stay (in
Philadelphia).  Last Sunday it was warm enough from mid-morning to
mid-afternoon to allow me to make a final winterizing check.  I'm pleased
to report that though I've lost a couple of hives to foulbrood (yes, I was
not using TM as a preventative but am re-evaluating this strategy, though
I don't plan to use it for prolonged periods if I do use it).  I have seen
*no* mites or signs of mites.  Nor does the oil (spearmint, applied per
Dr. Amrine's specification's) seem to be causing any problems for the
bees.  I used 1 gallon glass jugs, suspended by wire harness or duct-taped
furring strip (nailed via a single finishing nail) to the 2nd hive body so
that the jug's perforated top was about flush with the entrance.  The only
problem with entrance feeding was from yellow jackets in some locations (I
have three small yards and scattered single hives in community gardens).
I solved this problem by feeding the yellow jackets too.  (Seriously -
they get their own feeder placed a little away from the hives.  THey
seemed to prefer this over risking getting jumped by the guard bees at the
entrance-adjacent feeders, and I prefer the resulting reduced bee
mortality and hive agressiveness).
 
So, I don't know what this means in terms of the effectiveness of oils or
others' reported losses using wintergreen (my sincere regrets!), but it
at least didn't seem to do any damage.  Incidentally, I interrupted
feeding while introducing new queens to a couple of queenless hives in
September; things seem fine with these hives now.
 
It is important for me to note that even before initiating this treatment,
my incidence of observed mites was very, very low.  And it wasn't because
I wasn't looking.  Many a drone never made it past metamorphosis - I was
checking capped drones, mature drones, and bottom boards.  Before
treatment I saw perhaps 10 mites in 20 hives.  All season.  Total.  After
treatment I've seen no mites at all.  For that matter the fact that the
hives have made it this far into November and looked healthy is a vastly
different state of affairs from that existing a year ago.  -  Dave T.