Extended Release Oxalic Acid

Hi, I attended a presentation this week, in Middlebury, (Addison County Bee Club) concerning the extended use, by Jack Rath. (Previous owner of Better Bee) Jack had used it last summer and the year before, with a special exemption. He had really good luck with it. With 90 hives he had a 86% winter success.
The trick to use this is to start it early in the Spring, while the mite level is very low. (Or after another treatment) This is a long term method, 60 to 75 days, and works fairly slowly. If there are a lot of mites it does not work as well. The bees have to walk on the pads to effect the mites. The Vt. Agriculture Dept. has a recipe for preparing the oxalic, glycerine and pads (VBA too I think). If you try it be sure to follow the directions, heating temperatures, and safety equipment, rubber type gloves, safety glasses etc.
According to Jack it does not seem to adversely effect the bees/queen like other treatments (Formic for example). If you try it make sure the mite count is very low. I tried it last summer, without knowing all the instructions, and placed the pads with a too high mite count and also not the proper amount of square inches The Swedish sponges are 8 X 7, split in half the two pads, 3 1/2 X 8 are placed between the two deep hive bodies.
Following my treatment I vaporized the hives, several times, with Oxalic Acid and so far so good this Winter. I suggest you look at Randy Olivers, Scientific Beekeeping, to get more info.

Of all the organic acids, Oxalic is the easiest on the bees.

I used pads this past year. I can't report of efficacy due to low mite loads. I couldn't wash a mite and put OA pads on half the colonies mid May anyway. At the beginning of summer I couldn't wash a mite in the untreated hives but put pads on late June. In August I finally found one mite in an alcohol wash. Oddly, that discovery felt accomplished.

With that I can't report efficacy. Normally, in my area, low to no mite counts in early Spring will start becoming lethal late fall with little to nothing surviving winter. Without finding mites there's nothing to compare except the anecdotal. I believe the product is working yet can't actually prove anything. No sign of disease late fall wrapping and checked colonies this past warm spell to find them healthy. And that's all due to not seeing mites in washes all year. Is that due to the pads or have all the bee havers in my area finally given up beekeeping so my no mite load colonies didn't contract them? To say it's the OA pads is like saying I have a magic rock that keeps tigers away. I can prove it works because I don't see any tigers. I believe it works but can't prove it at this point.

I used it shortly after attending the workshop on how to do so correctly. Pads went on July 28 through July 30. Because it was so late and since I was getting a few counts at 4 mites per 300 bees, I also added Formic Pro strips on August 9. By September 15, my mites counts ranged from 0 to 4 per 300 bees (1/2 cup.) That's the lowest I've seen in mid-September. The colonies looked really good and still do now in mid to late winter for the most part.

The OAER strips will go on much earlier this year but I'll still be monitoring as usual. It's a hopeful new technique but, honestly, those crystallized glycerin/oa strips still need to prove themselves to me.

I don't have any mite wash numbers on colonies with pads. I can say that I did see control in some colonies. For example, I had two colonies in one apiary with significant mite numbers in the drone brood. Crawling with young mites in early May when the pads went on. In early July, these two particular colonies had frames of healthy capped brood, and combs of healthy, pearly white larvae. It needs more work to get the timing right, but I'm optimistic.