Oxalic Acid Only Kills Phoretic Mites

No varroa mite treatment is perfect. Oxalic acid treatments only kill phoretic mites. Those are the foundress mites that are riding around on the adult bees.

Most of the time, the majority of mites in a hive will be inside the capped brood. Oxalic Acid does not kill mites under the cap.

Oxalic acid is an organic compound that aids beekeepers in the fight against varroa mites. Oxalic Acid Vaporization is one of the best tools for varroa control. A naturally occurring substance, oxalic acid, is an effort to step away from the use of synthetic chemicals in beehives. It has shown to be very effective at killing mites when used correctly with no damage to the honey bee colony.

When varroa mites arrived in our country, the face of beekeeping changed forever.  These external parasites of honey bees weakened and killed thousands of colonies.

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Many large bee companies went out of business and almost all of the feral or wild bee colonies died.  Since the mid 1980’s, the fight between varroa mites and beekeepers has raged.

One of the biggest challenges of varroa mite control is this: How do you kill a mite living on a bee? The honey bee and the mite share some common characteristics. 

How can we kill the mite and not harm the bee?  What about chemical residues left behind in the honey and beeswax? Humans eat products that are harvested from the hive.

What is Oxalic Acid?

Oxalic Acid is an organic compound that occurs naturally in nature. It is a white crystalline solid that is colorless in water. You will find it in such things as: peanuts, sweet potatoes, wheat bran and pecans.

Some oxalic acid occurs naturally in honey. And, because it is not fat soluble it does not build up in the beeswax comb.

But just because it is a natural organic compound, that does not mean it is not powerful. Oxalic acid is several thousand times stronger than vinegar.

Oxalic Acid (OA) has been used by European Beekeepers for many years. With reports of 90-99% efficacy in killing mites, they found it be a useful tool in the fight with varroa. It was only approved for use in the US in 2015.

How Oxalic Acid Kills Varroa Mites

We know that oxalic acid kills mites. It is about 70 times more toxic to varroa mites than honey bees.

There is still debate over the exact way mites are killed. Whether it is through inhalation of the vapor or direct contact with spiky dried crystals.

One theory is that the vapor enters through the soft pads of varroa mite feet and gets into their blood stream. It may also damage varroa mouth parts.

With vaporization we are not trying to coat the bees, rather we are injecting the heated vapor into the hive.

As the vapor cools, small crystals are left behind on the bees, comb and hive walls. As worker foragers come and go-they will be exposed to the crystals.

Either way, we do know that it kills varroa mites with minimal dangerous affects on the bees. There are (at this time) 2 approved methods of using oxalic acid for mite control.