>  <<   When revising my hives a week ago and pulling the apistan strips
>  <<   I  noticed that I had around a 1 or 2 frames of brood per hive
>  <<   but no eggs.  However, when I went back yesterday to check
>  <<  they had around 3 to 4 frames of eggs plus frames of capped
>  <<  brood.
<snip>
>  <<   However, I noticed the correlation last year in that when the
>  <<  strips were in place I saw brood production decrease and
>  <<  then, the minute the strips have been pulled, I see egg
>  <<  laying dramatically increase.
<snip>
>      Sandoz have, of course, conducted tests on Apistan influence
>      (+ve or -ve) on brood and colony development/health; these
>      trials have been performed by various independent bee
>      institutes. All the results that we have suggest no influence
>      [of Apistan treatment] either way. I suppose the one effect
>      that is clear is that treated colonies do not die from Varroa
>      attack.
 
There are a number of things that can cause queens to stop laying.
we notice that sometimes the queens stop laying during rainy days in
the spring.
 
It is quite possible that apistan *may* reduce egg laying, however the
real question -- and what has likely been measured--  is whether Apistan
reduced actual *brood* rearing (as distinct from egg laying).
 
These are twovery  differnt things.  At many times during the year,
queens will lay many, many eggs that do not  become sealed brood.
The loss of this egg laying in itself will not affect the colony.
 
The deeper question is whether the presence of apistan affects the
queen -- either in short term, or in more permanent ways.  Tests
with queen tabs seem to show that queen cage tabs have deleterious
effects on queens that increase with time and ultimately end with
mortality.
 
However in hives, using recommended rates and durations of
application, my understanding is that the evidence is that queens are
not affected enough to harm the colony, although obviously there has
to be *some* effect of introducing a toxin.
 
Apistan is --like many of our control agents -- a selective poison
that has to be administered in measured doses.  we try to use enough
to hamstring or kill the pest without the effects on the host
becoming significant. this is a tradeoff.  No one has ever claimed
that Apistan is *good* for the bees in the absence of varroa.  It is
simply less harmfull by many orders of magnitude than the pest it
controls.
 
Regards
 
Allen
 
W. Allen Dick, Beekeeper                                         VE6CFK
RR#1, Swalwell, Alberta  Canada T0M 1Y0
Internet:[log in to unmask] & [log in to unmask]
Honey. Bees, & Art <http://www.internode.net/~allend/>