Things I did this winter while waiting for the bees - Part 2
Jan 24, 2012
At the end of summer I did treat for the varroa mite with Formic Acid and the colony had a low mite drop count, I decided to treat with Oxalic acid at the beginning of January. Oxalic acid is either mixed with sugar-water and then drizzled directly on the bees between the frames ( Emily from Adventuresinbeeland's blog demonstrates) or heated to where the crystals vaporize and rise up in the hive. Both methods kill the mite but must be done while the hive is pretty much brood-less as the oxalic does not kill mites in the cells. December-January is the best time to treat with Oxalic as the queen has not started to lay and there shouldn't be too much brood. Here is what the Vaporizer looks like. They can be home-made but this one was purchase from Heilyser Technology [caption id="attachment_601" align="aligncenter" width="600" caption="Oxalic Vaporizer"][/caption]
Here is a close up of the heating element. The oxalic crystals are placed in the tray then slid into the entrance of the hive.[caption id="attachment_602" align="aligncenter" width="600" caption="Vaporizer Closeup"][/caption] The entrance is sealed, I used some old shirts. If you use a screened bottom board that should be sealed as well as any other places where the vapor can escape. Like Formic acid, Oxalic will corrode the metal screens, so if possible remove them before treating. The leads are connected to a car battery for 1 minute, disconnected from the battery and left in the hive for another 10 minutes. The vaporizer is then removed and rinsed clean. Because Oxalic is quite a strong acid chemical resistant gloves and a respirator should be worn when working with it. Here is a picture of us treating a nearby neighbor's hive down on the next block. [caption id="attachment_587" align="aligncenter" width="600" caption="Treating friend's Hive"][/caption] My Neighbor experienced a mite drop of about 80 in a few days while my hive had about 35. From the research I found about treating with Oxalic is that it can be done up to 3 times a year using the vaporizer method but only once if drizzling it on the bees. I'm not sure which method is better but I do know that my bees have mites and the varroa population needs to be monitored constantly if the colonys are to survive.