Treating Your Bees with Natural Sources of Oxalic Acid
I have treated my colonies that needed treatment with shredded Thyme leaves with satisfactory results. When using shredded Thyme herb plant leaves it is the thymol in the plant oils that affects the mites in the hive. There has been some recent encouraging reports of success in treating bee colonies for Varroa mites with oxalic acid from shredded rhubarb leaves. I have not tried the shedding Rhubarb leaves treatment yet, but have plans to try it with my next required treatment.
Many plants we grow and eat contain varying levels of naturally occurring oxalic acid. The highest levels of the oxalic acid is found in Rhubarb leaves. Similar high levels can be found in the plants Lamb’s Quarter and Sorrel. The levels of the acid in the Rhubarb leaves is too high for safe human consumption. It is however safe to handle and process the leaves under normal conditions. The second highest levels of oxalic acid is found in the older leaves of chard, spinach, and beet greens. If you have ever bit into older leaves of chard, spinach or beet greens, you would have found a sharp bitter taste on the tongue. That is the heighten level of the acid. However, that level in older vegetable greens is not at the toxic level to humans as Rhubarb.
The shredded leaf treatment works with the bee’s dislike for anything foreign in their hive. The colony will drag smaller pieces through the hive and out the entrance. After shredding leaves, either with your hands or chopping them up with a knife, remove any stems and large pieces too big or tough for the bees to chew up. Spread a couple of handfuls out over the top of the frames in the top box and close up the hive. Any pieces too big to carry or drag out are chewed up and torn apart in their attempt to remove them. Moisture and oils from the plant containing oxalic acid is spread throughout the hive during the cleaning out process. It is very important to remember that with natural sources of Varroa mite treatments we aren’t trying to kill the mites. We are trying to apply a level of irritate to the mites that makes them drop off and not have a high level of adverse affect on the bee’s health. The concept of natural treatments is to help the colony manage a tolerable level of mite population themselves. I treat using natural treatments for low and moderate levels of mites. Natural treatments for the most part are to help keep a healthy colony healthy. That is why a natural keeper must always be vigilant in monitoring mite levels. If you discover a colony with an out of control, critical level of mites as in a “Varroa Mite Bomb” this is serious. You will lose this colony if you do not do intensive care treatment- now! This is not the time to debate commercial or natural treating or what is healthy or not or even what your personal feelings are. You have no time and nothing to lose using a commercial treatment product- they are going to die if you don’t. In the area of fighting the Varroa mite, don’t think of yourself as just a beekeeper, think of yourself as a mite manager. Again as I have stated in past columns, a sliding bottom board screen floor under your hive is the foundation of successful mite treatments. A keeper must know if they need to treat or if a treatment method is working. A SBB is an important tool for monitoring the need and effect of any treatment method. Even if you use commercial miticide treatments SBB monitoring is invaluable for confirmation of treatment success. Every year I hear the same thing from keepers, “I treated my hives for mites and they died anyway.” I know I don’t let up on the virtues the SBB, but with something insidious and deadly as Vaorra mites you have to be able to closely monitor,(at any time) the level of the threat and treatment results.
“It’s all about the bees”- Ernie