How to Fight Varroa Mites
Varroa mites have become a major concern for beekeepers. These tiny insects look like miniature ticks—they live by attaching themselves to bees and draining their blood, leading to the death of their hosts. The mites spread extremely fast and may lead to massive hive losses if left unchecked.
Controlling these insects is very difficult—most insecticides used to eliminate them can also wipe out bees and poison their honey. Thankfully, bee farmers have a few helpful tips for managing varroa mites. Some of the methods in this guide are not conventional, but they've helped several farmers get rid of the invasive pests.
Safety Note: Unless you're a bee singer, always wear protective gear when opening a hive.
Method 1: Use Essential Oils
Some research suggests essential oils have properties that can eliminate varroa mites without harming bees. Most essential oils have acaricidal properties, which means they can kill ticks and mites. A few oils that might fit this purpose are lavender, thyme and laurel.
Using a spray can, apply small amounts of the oil to your beehives right before introducing the bees. This is a preventive measure believed to repel mites. If your hives are already infested, you'll have to spray throughout. Make sure to get the dark corners where the mites may hide.
Method 2 - Powdered Sugar
Powdered sugar is fine grained enough not to bother bees (they'll clean each other off and eat the powder), but it sticks to the feet of the mites, causing them to lose their grip on their prey.
The downside of this process is that powdered sugar may contain cornstarch, which can interfere with the process of honey making and disrupt your harvest. Check labels when shopping for sugar so that you buy one with very little. Sugars that use anything other than corn starch as a caking agent can be dangerous for your bees.
Step 1 - Grind the Powdered Sugar
Grind one pound of powdered sugar using the baking flour sifter. You can repeat the process just to ensure there are no lumps. It helps to do this on a low humidity day, since moisture absorbs sugar.
Put the sifted fine sugar in a clean, dry container with holes on one end, like a baby powder applicator.
Step 2 - Drive The Bees Away and Disassemble The Hive
Smoke the hive to calm the bees, then open the hive. It helps to have a partner for this phase to speed things up.
Step 3 - Dust The Hive With The Fine Powdered Sugar
Take the frames one by one, and dust the sides and tops of each with the powdered sugar. When you're done, dust the tops of all the bars one more time together.
Although this method has yet to be verified by rigorous experiment, it has some anecdotal evidence to back it up. It's not a cure-all, but it appears to help somewhat. For best results, repeat it once a week, and use it in combination with the drone comb, as described below.
Use Drone Comb to Capture Varroa Mites.
This method uses the natural environment of the hive to capture mites. Varroa mites reproduce more on drone broods than worker broods, since drones take longer to reach maturity. Encourage your bees to develop drone combs by installing a special drone foundation with large hexagons on the sheets.
Step 1: Develop Drone Combs In The Hive To Attract Varroa Mites
Place one frame of drone comb in each hive, near the center, and leave the new frames for 21 days.
Step 2: Harvest The Infested Combs and Freeze
Remove the infested combs carefully and place in a freezer overnight. This will freeze the mites. Unfortunately, drone brood will also suffer the consequences.
Step 3: Return The Combs with The Dead Mites To The Hive
Uncap the cells with a knife or scraper, and place the combs back in the hive. The bees will invade the cells and clean them, using the waste products for their benefit.
Share Your Experience
As the science on this subject develops, varroa mites remain a major challenge for beekeepers. Bee populations are still dying at a staggering 40% or more each year.
If you have tips about helping hives, please share them to help others beat back these pesky mites. Leave a comment below, post about your efforts in our Projects section, or start a thread in our Forums about how to deal with these invaders.