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Subject: Orange County, NC Beekeepers

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  • From: John Rintoul <beecd AT icloud.com>
  • To: Orange County Beekeepers Association <ocba AT lists.ibiblio.org>
  • Subject: [ocba] Sampling for varroa - sugar shake vs alcohol wash
  • Date: Tue, 25 Jul 2017 07:56:13 -0400

I have been concerned that my varroa sugar shake was under-reporting the actual varna load in my colonies. So today I did a test.

I collected my bee sample, shook them with powdered sugar, and counted varroa. The count was zero. This colony had been treated with MAQS (formic acid) on June 20 so a low varroa count was expected. Nonetheless, the zero count reinforced my concern that sugar shakes don't accurately reflect the true varroa load in the hive.

So using the bees that had already been shaken with powdered sugar, I followed up with an alcohol wash. I swirled the alcohol and bees and let them set for a couple of minutes. Then I strained the wash off through a paper towel. A second alcohol wash yielded the same result. Varroa count = 0. 

So the sugar shake and the alcohol washes yielded the same result. This s a very small sample size for comparing sugar shake to alcohol wash. But my experience is consistent with the experience of bee researchers. They report that there is not enough variation between sugar shakes and alcohol washes to worry about. 

So from now on I will save the bees and trust my sugar shake technique. The sugar coated bees in the varroa sample are always welcome when they are returned - alive - to the hive. 

For new beekeepers - Now is the time to check the varroa loads in your hives. If my experience today counts for anything, you can assume that your sugar shakes accurately reflect the true mite load in hives. Treat to control mite loads accordingly. Use mite control products that are suited to the expected maximum daily temperature. MAQS (formic acid) below 95°F. Apiguard (thymol) below 105°F. Apivar (amitraz) without temperature limitations. Oxalic acid vaporizations or drizzle - if the bees are broodless. 

-John 

John Rintoul
(919) 414-4071
No trees or bees were killed in the distribution of this message, but countless electrons were seriously inconvenienced.



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