Robert wrote:
I can tell you no specific problem has ever seemed to me so genuinely vague
& complex as this varroa question,so I am far from dogmatic about whether
the hazards of Fluvalinate to bees and other spp are justified by the
benefits.

Hello Robert and All,
Because of your knowledge of chemicals you see the consequences of the
beekeeping worlds actions.  This post has no new information for me  as
Fluvalinate use is history in the U.S..  As with any problem you look at all
the possible solutions and make a choice.  In the U.S. we did exactly like
Europe and got the same result.  New Zealand looked at the possible
solutions and is doing exactly like Europe and the U.S. have done.
By 1989 over 100 of the worlds *most likely* chemicals were tried on varroa.
Fluvalinate was the best choice with the least side effects.  Many
beekeepers in the U.S. owe their survival so far to Fluvalinate.  Second
choice was Amitraz. Both Fluvalinate and Amitraz are only working in
isolated areas now. Coumaphous is working but resistance should surface this
spring if things go as in Europe. The other 97 are only 50% effective at
best.
I hope this post gets posted as I would hate to have to remove the statement
I am about to make to get the above posted. Please moderators!
Our U.S. researchers have said privately to me the worst is yet to come.
The last ten years were the good years with chemicals with 98% varroa
control.  We are now out of the most promising chemicals.  IPM measures like
varroa resistant bees,small cell size, screened bottom boards and drone
brood removal may be all there is.  It is true formic acid is providing some
control but when ever you don't get 100% kill you are going to get
resistance.  Formic acid gell should work for beekeepers in the south but is
to temperature dependent for nothern beekeepers unless they pull supers and
treat in August in the U.S..
If we were in a game of Chess with Varroa I would say we are in the end game
in the U.S..  We have made our best moves and now we await the conclusion.
The bee suppliers will tell you a miracle cure is right around the corner
but cures in beekeeping move slowly into beekeeping circles and I personally
see no cures at least in the U.S. ready to be released.  I have been on the
varroa front line since the start and still don't know the way things are
going to end.  I know our researchers have almost quit looking at chemical
solutions.
They even loooked at all the oils and such.  The best minds of the
beekeeping world have worked on the problem  both in Europe and the U.S. and
now all thats left is IPM and Russian queens.   Many of my friends think I
am obsessed with finding a cure for varroa and if they saw the problem as I
do they would see the urgency. Many researchers believe the varroa problem
will work itself out like the tracheal mite problem did but many commercial
beekeepers will go under with that senario while waiting.
Sincerely,
Bob Harrison