Varroa mites are among the top reasons beekeepers lose hives over the winter. As the bee population decreases in advance of the winter, the mite population increases, which further weakens the hive. These parasites can cause deformed wing virus and also lead to the death of the hive. Many treatments for varroa mites require either (1) no honey supers to be in place or (2) no brood to be in place (because mites like to party with the capped brood, i.e., lay their eggs in the cell with the developing larvae). I don’t want to needlessly treat my bees, so I wanted to check the mite levels to see if treatment were necessary. I learned so much doing this, but I also failed quite spectacularly.
The sugar roll test is a relatively easy and non-lethal way to check the level of mites in your colony. I spent the last week assembling my kit to check for mites. My kit includes:
- a large Rubbermaid container to store the kit and use for scooping up bees
- a quart-sized mason jar
- a number eight size mesh screen as a lid to the mason jar
- word of warning: just go ahead and order online; the hardware stores I spoke to didn’t seem to understand that screens came in different sizes
- a half-cup measuring cup (one half-cup = 300 bees, but don’t tap them down)
- a mister of water
- paper plates
- it’s easier to see the mites when they’re against monochromatic background
- powdered sugar
- I’ve heard contradicting information about whether bees can ingest corn starch, which is a common ingredient in powdered sugar. I couldn’t find any definitive answer (or powdered sugar without corn starch), so I went ahead and used a couple of tablespoons of powdered sugar and hoped the bees wouldn’t get dysentery.
Once you’ve assembled your kit, you’re ready to test for mites. It’s best to choose bees from a frame of brood because the mites prefer it. Put a half-cup of bees into your quart jar and sprinkle a couple of tablespoons of sugar on them. Screw the lid on and shake-shake-shake that jar. The bees need to be thoroughly coated, and shaking the jar also heats it up (thus further encouraging the mites to fall off). Then, turn the jar over like a shaker and shake out the sugar onto the paper plate. The bees are not harmed because they are too large to go through the mesh screen, and the mites fall through with the sugar onto the plate. Once you are finished shaking the bees, count up the number of mites. The number of mites will determine whether you should treat your colony.
Generally, it is recommended to treat your hive once it surpasses a certain threshold of mite infestation. If you are taking a sample when you have brood present, as I did, you should double the number of mites you count. It is strongly recommended that you treat your hive when your mite threshold exceeds 10-12 mites per 100 bees. For a useful infographic of the process, check this link out. At the recent NEKBA meeting, the presenter suggested that the threshold for treatment had recently been revised downwards to 3 mites per 100 bees.
With my newly assembled kit and my information on acceptable mite levels, I was armed and ready to determine the health of my hive. This is, of course, where my beekeeping fails come in. After both getting stung and realizing that my bees didn’t have enough honey in their hive bodies to get through the winter (their go my dreams of a honey harvest!), I diligently gathered my half-cup of bees, sprinkled on the powdered sugar, and started shaking out the mites. I was unhappily noticing the mites starting to accumulate on the paper plate when an unexpected gust of wind came and knocked my paper plate of mites and powdered sugar off my table.
WHAT?! (Actually, I’m pretty sure I said a word that rhymed with duck as I stared at place where my paper plate of sugar and mites had been).
So, after all that work, I have no idea how many mites are actually in my hive. I had already closed up most of the hive, and the bees were already pretty darn angry. It seemed best to wait until next week to try to determine the level of mite infestation.
So, my fails of the day include: getting stung, crushing my brief yet cherished dreams of honey, and watching my work literally blow away in the wind. Although a small part of me is disappointed about not having a honey harvest, my main goal as a first-year beekeeper is to not kill my bees. It was pleasant to dream about honey, but I’m also grateful that I don’t have to mess with harvesting honey this year.
My main lesson learned of the day is much simpler and more of the no-duh-Sherlock variety: put a darn rock on that stupid paper plate.