> Failure of OA treatment can be explained by the following:
 > 1. Failure of sublimation treatment:
 >          1. The ...screen ... is clogged with dead bees.
 >          2. Too much brood that have many mites
 >          3. bees robbing failing colonies full of mites

True.  In my case, however, I checked these things and was quite certain 
that I had reduced the varroa to low levels.  But, as with all these 
methods that are dependant on hive geometry, position of the cluster, 
etc., there were variations and there were a few exceptions which had 
levels higher than I liked, even after five sublimations.

I went into spring with acceptable levels, but found that the levels 
were too high for comfort by August.  OA was not an option then, but 
Apivar was.

The OA treatments had simply been unable to achieve the low spring 
varroa levels that Apivar can achieve.  With Apivar, we often see that 
after a spring treatment, no treatment is required in fall.

I believe that if I ran singles or doubles, that the results would have 
been better.  I could have improved the application method over using 
two simple Heilyser evaporators.  I think, for example, that blowing in 
the OA from the top with a special lid makes a lot more sense for me 
than injecting it into the bottom and is better for the operator and can 
be better monitored.

Personally, I just concluded that using OA sublimation at this time in 
my operation was too much work and resulted in variable success.  Using 
Apivar was simple and cheap, so I decided to go that way.  I guess now 
that I'll see how well that works for me.

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html