How to Control a Varroa Mite Problem in Your Beehive
A number of products and techniques are available that help reduce or even eliminate Varroa mites populations. This mite, which looks a lot like a tick, is about the size of a pinhead and is visible to the naked eye. The adult female Varroa attaches herself to a bee and feeds on its blood (hemolymph fluid).
In recent years, it is a generally accepted practice not to medicate your bees unless you know it is necessary. Medicating your bees as a protective measure can actually diminish the effectiveness of medication when you absolutely, positively need it. The mites can build a resistance when medications are used too frequently.
Medication options or Varroa mites in your beehive
There are a few effective and approved miticides (chemicals that kill mites). When you confirm Varroa mites in your colony, you must immediately treat with one of these treatments by carefully following the directions on the package.
Because Varroa mites can develop a resistance to these medications, it is prudent to alternate between two or more of these from one season to the next.
Apistan is packaged as chemical-impregnated strips that look kind of like bookmarks. Hang two of the plastic strips in the brood chamber between second and third frames and the seventh and eighth frames. You’re positioning the strips close to the brood so the bees naturally come into contact with the miticide they contain. The bees will brush up against each other and transfer the fluvalinate throughout the hive.
Never treat your bees with any kind of medication when you have honey supers on the hive. If you do, your honey becomes contaminated and cannot be used for human consumption. Feeding medicated honey to the bees is, however, perfectly okay.
Some mites have developed a resistance to Apistan, so new miticides have entered the market. CheckMite+ is a product manufactured by the Bayer Corporation (of aspirin fame). Like Apistan, it also consists of strips impregnated with a chemical miticide. It’s tricky to use safely. New beekeepers should steer clear of CheckMite+ until they gain experience.
Mite-Away II (Formic acid)
Formic acid is available in gel packs, but it is caustic and tricky to administer.
Apiguard is a natural product specifically designed for use in beehives. It is a slow-release gel matrix, ensuring correct dosage of the active ingredient thymol. Thymol is a naturally occurring substance derived from the plant thyme. It is easy to use and much safer than formic acid or coumaphos. You might try alternating between Apistan and Apiguard if you need to treat your bees for Varroa mites.
Natural options for treating bees with Varroa mites
You don’t always have to use chemicals to deal with Varroa mites. Integrated pest management (IPM) is the practice of controlling honey bee pests with the minimal use of chemicals.
Use Drone Comb to Capture Varroa Mites. Bee suppliers sell a special “drone” foundation that has larger hexagons imprinted in the sheet. The bees will only build drone comb on these sheets. That’s useful, because Varroa mites prefer drone brood over worker brood.
By placing a frame of drone comb in each of your hives, you can “capture” and remove a many mites. Once the drone cells are capped, remove the frame and place it overnight in your freezer. This will kill the drone brood and also the mites that have invaded the cells.
Then uncap the cells and place the frame (with the dead drone brood and dead mites back in the hive. The bees will clean it out (removing the dead drone brood and mites). The cells will get filled again, and you repeat the process.
Powdered Sugar Dusting to Control Varroa Mites. This involves dusting the bees with powdered sugar (note it’s best to find a powdered sugar without added corn starch, although some claim this is not so critical. Play it safe and ask your bee supplies for a “pure” powdered sugar).
Here’s the process:
Sift a pound of powdered sugar using a baking flour sifter. Do this twice to ensure no lumps. This should be done on a day with low humidity.
Put the sifted sugar into an empty (and cleaned), baby powder container (alternatively you can improvise your own container).
Smoke and open the hive.
Remove frames one by one, and dust the bees with the sugar.
Avoid dusting any open cells.
Put the dusted frame back into the hive and repeat this process with each frame.
When done, but a little extra dusting along all the top bars.
This should be repeated once a week for two to three weeks.