> There have been reports that Apistan was "re-formulated" and the current 
> fluvalinate is a different version than the original, much more potent.

What I have been told is in 1995 the formula changed to a tau fluvalinate. 
However many of the former strips were still in bee supply houses.

The first fluvalinate was only mildly toxic to bees but the tau fluvalinate 
is rated very toxic to bees.
I think the problem started when the mites started becoming resistant to 
fluvalinate and in some cases beeks starting increasing  the number of 
strips being used. 2 in the bottom box and two in the top were not unusual.

I am always surprised when many beeks gasp at fluvalinate and coumaphos 
being the highest chemical found in brood nest comb by researchers. 
Fluvalinate has been registered for bees in the U.S. for almost two decades 
and coumaphos for around a decade. Most bee supply houses sell both.

Why wouldn't both be the most found chemicals with the highest levels?

In a recent experiment I placed bees on old comb which had both checkmite & 
apistan ( not tau fluvalianate) used for years. Nice frames of brood and the 
larva were snow white.

I have not used apistan or checkmite myself for many years and have changed 
all my combs.

The problems I see in my yards now is nosema ceranae and to be honest some 
virus issues in my opinion I which should not be  seeing as I have had 
excellent varroa control this spring. Although only an occasional cell or 
two I see larva problems and only in late stage larva. Four beeks looked at 
what I am seeing and all had different opinions. Two thought possibly stone 
brood and two not sure but all thought was not European foul brood.

Not really a big deal right now with supers on but I am keeping a eye on 
those hives to check after supers are pulled.

It is a possibility I have got a light infection of European foulbrood and 
plan on ordering a test kit from dadant on my next order. The hives I pulled 
the brood from for those hives I treated for European but those hives have 
had no treatment.

Again these hives were completely taken apart and gone through by four beeks 
, brood and stores counted and all frames observed.

We took apart four of this years Russian/Russian hives. Found one with a 
cell of chalkbrood ( a first) , three out of four had superceded the marked 
queens. In fact two of the supercedure queens were virgins. The marked queen 
had a great brood pattern. These are only four of the hives I have started 
so may not be represntive of all.

it is what it is. Please do not kill the messenger!

Despite what some say hives disturbed the least produce the best when all 
factors are the same but in test yards complete disassembly is best to 
evaluate a hive. regardless of the time involved. if you have got a yard of 
bees with problems pick a couple hives and tear all the way down and observe 
all frames and bees.

bob 

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