Using Oxalic Acid Vaporization to Kill Mites in Beehives
Oxalic Acid Vaporization is one of the newest tools in the beekeeper’s fight again varroa mites. As a beekeeper, you have several different strategies to use for mite control. Oxalic Acid, a naturally occurring substance, is another effort to step away from the use of synthetic chemicals.
When varroa mites arrived in our country, the face of beekeeping was changed forever. These external parasites weakened and killed thousands of colonies.
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.
How Oxalic Acid is Used for Mites?
Oxalic Acid is an organic compound that occurs naturally in nature. You will find it in such things as: peanuts, sweet potatoes, wheat bran and pecans.
Oxalic Acid (OA) has been used by European Beekeepers for many years. They found it be a useful tool in the fight with varroa. But OA, was only approved for use in the US in the last few years.
There are (at this time) 2 approved methods of using oxalic acid for mite control.
One is the “dribble method” where OA is mixed with water and dripped on the clustered bees. This method must be done carefully with the correct strength and volume or you can kill your colony.
Another method is “oxalic acid vaporization“, OA crystals are placed on a special wand. The wand is inserted into the hive and heated to vaporize the crystals.
You can read more about the various mite treatment methods available to beekeepers in my post : Best Varroa Mite Treatments.
The wand I am using is called the Varrox from Oxavap. However, the one picture above has many good reviews. It would be my second choice.
How to Use Oxalic Acid Vaporization
This is an overview of one way to use oxalic acid with a vaporizer in your bee yard. Please use appropriate safety gear to protect your skin and lungs.
Is it time to treat your bees for varroa mites? When should you treat your hive? Perhaps you have a high or increasing mite count and know you need to act now.
Let’s gather our materials and head out to the apiary.
- safety gear – as directed on OA label
- oxalic acid crystals
- oxalic acid vaporizer
- power source for vaporizer
- measuring spoon
- bucket with cool water (if your model allows cooling)
- rags, old towel, etc – to use as temporary plugs
- grid board – if you have screened bottom boards
You should keep most of your oxalic acid vaporization tools together. I use an old plastic cat litter tub. Anything will work.
When Should Your Treat Your Bees?
It doesn’t matter what time of day you do your treatment. But, I think the hives are less fussy early in the morning.
Following all safety precautions as set forth on the Oxalic Acid label-proceed with the following steps.
Oxalic Acid Vaporization Steps
- insert grid board under screened bottom boards
- Remove hive top and loosely plug the hole in the inner cover
- measure the required amount of oxalic acid and place on cold wand
- slowly insert vaporizer wand into the front of the hive
- lay an old towel (or similar) across the front
- connect vaporizer to power source
- set your timer (2.5 – 3 min?) time depends on vaporizer model
- energize the vaporizer and stand upwind from the hive
- at the end of the timer, let the vapor cool a few minutes before removing the wand
- wait an additional 8-10 min before opening all the entrances and ventilation ports
If Brood is Present – Repeat Treatment
No varroa mite treatment is perfect. Whenever, you treat your colony be sure to recheck in a couple of weeks to make sure it worked!
Most of the time, the majority of mites in a hive will be inside the capped brood. This treatment does not kill mites under the cap.
However, oxalic acid vaporization is an effective mite treatment for mites that are on the adult bees.
An effective method used by many beekeepers is to give the hive 3 treatments that are 5-6 days apart. In this way, most of the mites will be out of a cell and exposed to treatment.
How many times a year do you need to treat for varroa mites? It depends on several factors including the genetics of your hives and where you live. Mites are a bigger problem in some regions.
Oxalic Acid Vaporization is an effective way to manage varroa mite numbers in your beehives.
Use all safety precautions and recheck your colony for effectiveness a couple of weeks later.