August is the time of year many beekeepers start thinking about managing colonies to set up for the long winters in Minnesota and Wisconsin. One of the most important aspects to this is making sure that they have a good Integrated Pest Management Plan (IPMP) for the colony so it is strong and disease/parasite free going into the winter.
The varroa mite is an external parasite of adult bees and brood that weakens colonies progressively throughout winter months. It sucks the hemolymph (similar to blood) of bees and weakens bees making them more susceptible to disease, decreasing lifespan and sometimes killing bees outright. A good IPM strategy is to monitor each colony (or for large apiaries 12-15% of their hives) for mites before treatment is considered. If the bees are relatively mite free i.e. below threshold, you may not need treatment. However, its important to remember with long winters in the North, even a low threshold of mites could mean problems. It’s important to remember treatment needs to be started by early September so bees have enough time to hatch brood and make honey for winter from the late autumn bloom.
There are many great tutorials on how to test your hive for the presence of the varroa mite. I’ve included instructions in the links below:
Sugar Roll Method from the University of Michigan
Sugar Roll Method from the University of Minnesota
If you have questions, need more information or want assistance in an Integrated Pest Management Plan, please don’t hesitate to contact us!
Dr. Eva Reinicke