This thread is not getting much help.  C'mon people!

How about this one:

BeeGo loses its effectiveness after the container is opened, if damp air is
in contact with it.  Water neutralizes the efectiveness of n-butyric
anhydride as a bee repellant.

I first heard it here on BEE-L, I believe.

allen
http://www.internode.net/HoneyBee/Diary/