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-----Original Message-----
From: Adony Melathopoulos [mailto:[log in to unmask]] 
Sent: Monday, October 08, 2007 12:46 AM
To: [log in to unmask]
Subject: Re: [WL] [BEE-L] Fumidil B dusting

On Sat, 6 Oct 2007 19:54:35 -0400, Adony Melathopoulos
<[log in to unmask]> wrote:
>The colonies in Langley were either left untreated or treated with a 
>total of 300 mg fumagillin applied weekly over three weeks, beginning 
>on March 14th.  The same dose of fumagillin was either applied in 
>powdered sugar or in syrup.  The nosema levels among untreated colonies

>shot up and by April 12th levels had reached 1.6 million spores per
bee, a four-fold increase.
>By contrast, both methods of administering fumagillin, either in syrup 
>or dust, resulted in nosema levels below 100,000 spores per bee.  
>Clearly, dust was as effective as syrup.

I was talking with Medhat Nasr and pointed out a very important
distinction between the two studies that I failed to mention in the
post.  While in the Beaverlodge study they applied their 58.8 mg
fumagillin active in a small amount of icing sugar (one application of
two teaspoons / colony and a second application in three
teaspoons/colony), the Langley study employed a massive amount of sugar,
three treatments of 300 mg fumagillin across 3 x 7lbs biweekly
treatments in powdered sugar... this sugar, of course, was not sprinkled
on the colony, but rather "was fed in top feeder trays and placed
directly over the brood chamber".  So, in addition to the studies being
performed: 1) in different locations, 2) with different initial levels
of infection, 3) using different doses, they also differ by 4) the way
the powdered sugar was administered.  While this makes comparison
between the studies problematic, I still think the mediocre performance
in Beaverlodge should not be written off until a dose closer to the
label is tried out - slightly higher than label doses certainly seemed
to work in Langley.  

The time has come to revisit this issue and hopefully in the coming
years there will be new data to help support or reject the use of sugar
dusting fumagillin.

Finally, in the event that you did not realise it, dusting fumagillin is
an off-label use of the product - it is clear why this is - while there
is a stack of studies confirming the use of fumagillin in syrup feed,
there is no clear verdict on how fumagillin works in a sugar dust (or
syrup spray for that matter). This is how it often is with off-label
uses - the data is skimpy.  A phrase in one of Bob Harrison's posts is
apt here: "A shelf full of products not applied correctly is a waste of
time and money".  Not only time and money, but incorrectly applied drugs
can contaminate honey.

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