>  Is there any harm in proactively treating with OA vapor while they are clustered?

I was always under the impression that disturbing a winter cluster was a very bad idea and should be avoided at all costs. For example: 

> Opening the hive and disturbing the cluster to collect bees in cold weather can be detrimental to the colony, and may even kill it. -- Journal of Apicultural Research 5(1): 63- 64 (1966)

> Factors against winter treatment are the bad effects of disturbing the winter cluster of bees and the difficulty of observing the reactions of the bees to the chemical substance. -- Guy D. Morison Ph.D., M.Sc. (1931) Comments on Chemical Treatment of Acarine Disease, Bee World, 12:8, 89-90

By the way, in the above mentioned article, the treatment was for tracheal mites and one of the treatments was:

> a chemical mixture (2 parts nitrobenzene, 1 part safrole, 2 parts petrol) is known which kills all stages of the mite inside living bees. 

PLB

             ***********************************************
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