Oxalic acid is one of the treatment options for Varroa mites – arguably the arch-nemesis of the honeybee today. Varroa mites have made beekeeping a challenge since they made their way to the United States in the 1980s. They cause some direct problems, like wing deformities and spreading viruses. They also cause indirect problems by weakening the immune system, which opens the door to other problems. I have yet to see a hive totally free of Varroa mites. Therefore, our goal as beekeepers is to keep their numbers low in our hive. One way to do that is to treat them with an oxalic acid drip, which I will describe in detail in a future blog.  Oxalic acid can be purchased online through Brushy Mountain Bee Farm

What exactly is oxalic acid? It is an organic compound with the formula H₂C₂O₄. It has no color, appears as a white crystalline powder, and dissolves in liquid. There are benefits and drawbacks to nearly every mite treatment, but I have to say oxalic acid is the one treatment with the most benefits and least amount of drawbacks that I have used. Further, this substance was just recently permitted for Varroa treatment in the USA, which makes it an accessible option for us backyard beekeepers!


Synthetic chemical treatments and essential oils may leave traces in the honey. Oxalic acid is a natural component of honey, and doesn’t leave unwanted traces.
It’s a natural and organic substance found in plants, like spinach and rhubarb.
It is not lipid and will not build residues in the beeswax.
It’s easy to apply! Follow my next two blogs for information how to mix it and apply it.
If applied correctly, it is very deadly to the mites but very safe for the bees. Studies have shown an 82-99% efficacy!

This acid is corrosive, and can be dangerous if applied incorrectly or too frequently.
It is most effective when a hive is broodless. Therefore, it is best to apply in the late fall or winter only and not a good treatment option for the summer or early fall.

I have encountered many new beeks (beekeeping geeks) that are nervous or apprehensive to treat their hives for mites with a foreign substance. I can’t say that I blame them. It’s not ideal to throw anything into our hives that are not natural. The tough truth is the Varroa mites will take advantage of any hive, without discretion, no matter how much you love and care for it. The only viable option is to take routine mite counts, which I have discussed in a previous blog and treat if the percentage is above a manageable threshold. The good news is I have found several treatment options that I feel good about as a beekeeper, and oxalic acid is one of those options. I feel good about it because of the advantages I describe – it works and it is a more natural option than a harsh synthetic chemical. I want my bees to keep buzzing, season after season, and year after year. I hope yours do the same!

Keep your bees buzzin’ y’all!

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