Subject: Re: Formic acid?
From: M&L White <>
Date: 2000/09/26
Newsgroups: sci.agriculture.beekeeping

Here in Canada we have been using Formic Acid starting around 1994. In the past few years testing has been done at the University of Guelph in Ontario in conjunction with Ontario Beekeepers Association, and the Ontario Ministry of Agriculture, food and Rural Affairs to developed a single application of Formic Acid. Their research came up with this method. You will need 65% Formic acid 1/2 inch Tentest board also known as (Homosote) see your local building supplier or lumber store. 12 inch by 12.4 inch Ziplock vegetable bags. These are perforated with small holes to allow moisture out. 12 inch by 12.4 inch Ziplock freezer bags. 2 of per hive 1/2 inch by 4 inch spacers 1 of per hive A 1 inch spacer to sit on top of your brood chamber to raise up your cover

Cut the Tentest board into 8 inch by 9.6 inch and place in the Ziplock vegetable bag. Place the pads in a plastic pail standing on their ends. Add the recommended amount of Formic acid 2.5 Liters for 10 pads or about 250 ml for 1 pad. Seal the pail with a tight lid then after 3 days rotate the pads 180. After 2 days the pads should have absorbed all the acid. Place them still in their vegetable bag in the Ziplock freezer bag. This will seal them until you are ready to use it. Preferred timing for application Spring or Fall. Day time temperature 12 to 25 C. Night time above 7 C. Leave in hive for 15 to 21 days. To apply. Place your two 1/2 inch by 4 inch spacers on the top frames of the brood chamber, pull the pad out of the freezer bag leave in the vegetable bag and place on the spacers. Place your 1 inch spacer on the brood chamber then put your lid back on the hive. Your done. I think the idea is the acid gas is heavier then air ( not sure, I'm not a scientist ) so it should be up in the top chamber. The 1 inch spacer that raises you hive cover reduced the evaporation rate when it is cool. The 1/2 inch spacers the acid boards sit on is to keep it off your frames and to get air circulation around it. The Ziplock vegetable bag regulated the evaporation rate.

Good luck

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