Thunder Bay Beekeepers were passionate about keeping their area free of mites but were recently infested by Varroa destructor in spite of their best efforts to keep it out.
We hope your area is more successful, and here is why. Keeping the number of mites down in a colony is a neverending job and requires labor-intensive monitoring of the population of mites in each hive. If the number of mites gets too high, the colony will die.
The beekeeping industry is encouraged to rely on chemical solutions to treat colonies before death occurs. Most of them cannot be used at all when honey boxes are on the hive, as they are toxic and would contaminate the honey. There is a very small window of time in the north before and after the honey flow when the temperatures are right for delivering the treatments.
Chemicals may keep the colony alive but may still contaminate the beeswax and afterwards the honey we feed our families. Low-level pesticides are also harmful to bees, sometimes killing whole colonies or their queen. Many are dangerous to the beekeeper administering the treatments. The chemicals are expensive and their side effects may raise human health concerns.
There are other non-chemical methods of attempting to control the mite, but these are not practical for anyone with more than a few colonies.
One thing that holds promise is breeding for mite-resistant bees. After year of selecting, we do have hygienic bees here, resistant to many brood diseases of bees. Hygienic (cleaning) behavior has also been shown to be an important element in mite resistance. Such bees detect mites in the sealed brood cells, uncap them, and throw the infected larvae and mites out of the hive. Bees grooming each other also reduces mite populations. Selecting for these mite-resistant behaviors in our locally adapted honeybees would be desirable and reduce the need for chemical treatments.
Jeanette Momot
M.S. Biology
(Bee Genetics and Apiculture),
Ohio State University
Slate River, Ontario
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