>>I am thinking the problem with fumigant type
treatments and screened bottom boards is the inability to get a tight seal
on the screened bottom and leaking of the fumigant.

It wasnt clear from your description if you use only a screened board or if you place it over a solid board ( which I turn backwards so that bees dont fly btwn it abd the SBB, and also to be able to slide in a used file folder from the back to monitor mite drops). If the latter, it doesnt add much to the treated volume, the bees quickly propolize and seal any cracks, and with formic you are meant to leave the entrance open. For formic acid, perhaps examine the timing, temperature, concentraion of and volume of formic acid on the application pad, number of tx and time btwn changing pads if multiples are used. 

You are connecting sub optimal mite kill to losses, how are you determining pre and post treatment mite numbers?

Where are you located? This time of year would be very early for northern hives, so just wondering how your local management timing works


Greg
Everton ON Canada
Sent on the TELUS Mobility network with BlackBerry

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