Varroa mite counting, round 3.

On 6/20/2013 (this makes this post somewhat out of order), I removed the sticky board from beneath each hive.  The boards had been in for about 4 days.  Unfortunately, I lost track of when I placed the boards, but I did note that I removed them on 6/20/2013 at 1750.

Hive A had only 1 mite on the board.  Hive B had 10 mites on the board.  On 6/16/2013, Hive A had a population of about 9,375 bees (7.5 frames full of bees x 1,250 bees per full frame).  On the same date, Hive B had a population of about 12,500 bees (10 frames full of bees x 1,250 bees per full frame).  Again, we are going to say that this is over 4 days of collection.

• Hive A:  1 mite per 9,375 bees per 4 days = 1/(9,375 x 4) = 0.03 mites per 1,000 bees per day.
• Hive B:  10 mites per 12.5k bees per 4 days = (1/12,500 x 4) = 0.2 mites per 1,000 bees per day.

So, from the numbers above, I feel that I am comfortable not treating for mites at this time.  The quote that I am following, you might recall, is the following:  "If your sticky board count shows more than 2 mites per thousand bees per day in mid-August or more than 4 mites per thousand bees per day in September, you should find a way to reduce the mite population."

Even if the boards were only in for one day--and thus the mite numbers would be 0.12 and 0.8 mites per thousand bees per day--there would not be a clear indication to treat.

After this mite count, I did not get to a mite count for over a month.  I did an about 2.5-day mite count that ended on 8/3/2013.  There were significantly more mites, but there were also significantly more bees.  I'm hoping to do an inspection over the weekend of 8/3/2013 so that I can get a good estimate of numbers of bees.