Varroa mites are the kryptonite of beekeeping these days. Keeping their numbers in our hives to a minimum is key to successful hive management. In my previous blog I described how I count the mites in my hives using a random sample. Now the question becomes – how many mites is too many? As with most things in beekeeping, it depends on who you ask.

First, let’s do some math! I did an alcohol wash with 1/2 cup bees (about 300 live bees) and found three mites. This translates to one mite per 100 bees. However, this only accounts for the living and emerged adult bees, and not the unemerged brood. The queen is still laying a lot of eggs in July/August. Therefore, I double this number to account for those unemerged bees to get two per 100 or 2%. My second hive was a whole different story. I counted 28 mites per my 300 sample. This equates to 18.6%, which is heartbreaking (and frankly embarrassing) to me as the beekeeper. Below is a picture of the mites that are easy to see with the human eye:


Below is the formula to calculate the number of mites in your hive when using a 1/2 cup of bees (roughly 300 bees) during the height of their population:

M= number of mites in sample
P= total mite percentage

Now to answer the question – how many mites is too many mites? I reach out for advice from those beekeepers who have proven themselves successful. Dr. Dewey Caron is one of those beekeepers. The link below takes you to an article he wrote about varroa mites that is phenomenal. I use this as a guide for my mite management.

Click here for the pdf from the page.

I did my count at the beginning of August, when the hive population is at its highest. Therefore, anything between 3-5% is concerning and anything above 5% is dangerous. My first hive at 2% is doing pretty well, but my second hive at 18.6% and is not looking good. I don’t know if my hive will survive through the winter, but I’m going to give it my best shot. The next question becomes – well, what do I do with my hive that is suffering? What do I effectively reduce the number of mites?

Check out my next blog that discusses the options for treatment and the option I chose.

Keep your bees buzzin’ y’all!