An effective, sustained-release method that doesn’t require opening the hive repeatedly.
If you’re looking for a low-intervention way to manage varroa mites, oxalic acid pads may be the most convenient option. These pads deliver a continuous, controlled release of oxalic acid inside the hive—targeting mites over several weeks without disturbing the bees.
This technique, developed and extensively tested by Randy Oliver of ScientificBeekeeping.com, is especially useful for hobbyists and sideliner beekeepers looking to reduce mite levels during times when other treatments are less ideal.
What Are Oxalic Acid Pads?
Oxalic acid pads are shop towels or cellulose pads soaked in an oxalic acid and glycerin solution. Once placed in the hive, the glycerin slowly releases the oxalic acid, which coats the bees and the hive environment, disrupting mites over an extended period.
Randy Oliver has published detailed instructions, formulas, and trial data showing its efficacy across multiple environments. If used correctly, it provides sustained mite suppression with minimal risk to the colony.
When Should You Use OA Pads?
This method works best when:
- You need a low-effort, extended treatment that doesn’t require multiple hive openings.
- Brood is present (but capped brood will still limit effectiveness).
- You’re treating nucs or single-deep hives during buildup or after splits.
- Temperatures are stable and not extremely hot (which could cause the pad to dry out too quickly).
It’s not a “knock-down” treatment like vaporization, but it’s an excellent option for gradual mite suppression, especially when you’re trying to avoid frequent hive disruption.
Materials You’ll Need
- Oxalic Acid (labeled for beekeeping use – source locally)
- Glycerin (USP grade)
- Cellulose shop towels or cotton pads
- Accurate digital scale
- Protective gear (nitrile gloves and acid-rated respirator)
- Glass container or stainless-steel pot (for mixing)
- Zip-top bags or sealed containers (for storage)
How to Make the Pads
Here’s a simplified version of Randy Oliver’s recipe (check his full instructions for precise ratios and updates):
- Mix your solution:
A common ratio is 25g OA : 20ml glycerin, which saturates one shop towel. - Apply solution to towel:
Lay the towel flat, then pour the measured solution over it until evenly absorbed. - Store properly:
If you’re not using them immediately, seal them in an airtight bag. Keep out of sunlight and away from children or pets.
How to Apply the Pads
- Wear full PPE:
Gloves and a respirator are a must. OA is safe when used correctly, but direct contact can cause harm. - Open the hive:
Gently lift the outer and inner covers. - Place pad(s):
Lay one saturated towel on the top bars of the brood nest area. Some beekeepers split one pad between two spots if space is tight. - Close the hive:
That’s it! No vaporizer, no repeat visits for weeks.
Treatment Duration
The pad gradually releases OA over 30–45 days. Replace as needed if mite levels remain high or if the towel dries out prematurely.
Benefits of the OA Pad Method
✅ Easy to apply
✅ Sustained release without re-entry
✅ No specialized equipment
✅ Gentle on bees when used properly
Cautions & Considerations
⚠️ Pads should never touch open brood directly
⚠️ Ensure correct OA-to-glycerin ratio
⚠️ Not effective for heavy infestations alone — perform mite counts regularly to monitor progress
⚠️ Do not place pads during honey flows unless you’re absolutely sure it complies with your local beekeeping regulations
Final Thoughts
Oxalic acid pads are a powerful tool in your mite management toolbox. They’re not a standalone solution, but when paired with regular monitoring and other integrated pest management techniques, they can help keep varroa in check throughout the season.
For the full science, ratios, and field-tested application methods, visit Randy Oliver’s research at ScientificBeekeeping.com.
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