Hello All,
Not all beekeepers do the amount of varroa testing i do so i thought i would
share my results,observations and comments.  With all but two remote yards
in now i am beginning to get a varroa picture for the season.
All production yards were treated with coumaphous this spring.  All yards
were rechecked and treatment was in the 98% range as per post treatment
sticky board tests.  All yards were checked about a month ago for normal
mite fall to see if supers needed to be pulled and fall treatments begain.
All sticky board levels were ok but highest in areas next to beekeepers
which had used apistan last spring.
All yards tested so far are showing varroa mites.  Levels are the highest
in yards bordering yards treated with apistan.  I tested those yards with
apistan strip and sticky board first.  Not many mites and half were still
alive on the sticky boards after 24 hours.  I then pulled the apistan strip
and put in a coumaphous strip.  When i pulled the sticky boards 24 hours
later  the boards had a normal amount of mites(about five times the
amount with apistan) for this time of year and unlike apistan ALL mites were
dead. I have yet to remove a sticky board from a coumaphous strip tested
hive and find a live mite.
My conclusion is that i am seeing a similar situation as i did in the spring
of 1996 when the problem was reinfestation from beekeepers not using any
treatments at all and robbing of feral colonies only this year the problem
is from beekeepers using fluvalinate and getting only a 50% or less kill of
varroa.  Both said beekeepers are reporting huge populations of varroa and
pitiful honey crops.
I had planned to use apicure on all hives if mite loads were low but now i
am going to have to use coumaphous on those yards close to those beekeepers
to keep from losing those colonies.  The fall honey flow started about a
week ago so robbing might stop for now but i imagine quite a bit of robbing
has gone on from weak colonies.  In 1996 reinfestation caused many hive
losses even in hives treated in the spring.  Apistan was about 98% effective
then but still the reinfestation rate was causing problems.  Bees were
arriving back at the hives with varroa mites hanging all over them.
Please test all your hives if using apistan or even apicure as your control
problems effect your fellow beekeepers efforts.
Sincerely,
Bob Harrison