Updated: Jun 26
As a beekeeper, there is no doubt you are familiar with the pesky Varroa Destructor mites. Not only do they attach themselves to honeybees to feed on their fat body tissue, but they are responsible for the transmission of over a dozen viruses associated with the decline of honeybee health. Varroa mites have contributed to annual colony loss rates exceeding 30% and have been linked as a cause of Colony Collapse Disorder.
As you prepare your hive for winter, you need to determine if your hive has Varroa mites and if so, the level of infestation. Our winter checklist blog post outlines the steps to master the alcohol wash test, a challenging but extremely accurate way to count mites. Any count above three mites in 100 bees (3%) means immediate action needs to be taken to save the hive.
The Oxalic Acid Dribble is one of several treatments recommended by Strong Microbials to keep mite load under control.
Treatment: Oxalic Acid Dribble
Slava and Vera used the API-Bioxal brand of Oxalic Acid for this procedure. It is currently the only EPA-recognized oxalic acid product for in-hive use and the only way a beekeeper can apply oxalic acid to their colony for varroa mite control. Formic and oxalic acid disrupts the metabolism of the mite in a natural way. They are less likely to develop resistance, compared to alternative pesticides, and they degrade faster in the environment. Exercise the highest levels of caution possible when using any chemicals in your hives. All options may halt brood production and can potentially kill the queen.
1. Add 24mL of 3% solution per colony.
2. For precise delivery, small operations use a graduated syringe that can be purchased at any beekeeping supply store.
3. Large commercial operations use a cattle drench gun that can be set to 24mL. Oxalic acid is placed in a 2-gallon camping shower bag that can be carried in a backpack. 2 gallons of oxalic acid solution can treat 315 hives.
4. Repeat treatment within one week of initial application.
If gone untreated, the Varroa mite infestation will overcome your honeybees and spread to neighboring hives, and beyond. Help your bees by monitoring and treating for Varroa on a regular basis.
For a full guide on Varroa mite management, check out these free tools and resources from the Honey Bee Health Coalition.