Varroa Testing: Alcohol Wash vs Sugar Dusting method

It is the time of the year to determine varroa mite levels in the hive. I want to know the mite level to understand the severity of the infestation to determine the frequency of how often I should be treating the hive once I pull the supers out for harvesting.

In beekeeping literature, there are several methods to test for varroa mites and the method widely practiced in Vancouver is the alcohol wash. An alcohol wash requires you to capture 300bees about 1 cup into a bottle and pour anti-freeze wiper fluid (alcohol) to remove the varroa mites from the captured bees. The alcohol is poured out and the varroa mites flows out with it. You then count the varroa mites and multiply by 100 if you don't have brood or multiply by 600 if you have plenty of brood. The bees to be captured should be from the brood frames, so preferably nurse bees or drones.

I have been against this idea of alcohol wash and I was putting the idea of testing for varroa mites away all together. I thought why drown 300 precious nurse bees for this method. Nurse bees are the main food provider of the queen bee and growing larvae, as nurse bees vittelogen levels are the highest which is a component of the elixir we know as royal jelly. As some would know, the queen been is only fed with royal jelly. Nurse bees also support the growing larvae with worker jelly which are very demanding. At any one time in a healthy hive with a good laying queen, there are 8000+ larvae calling out for food.  So drowning 300 nurse bees will reduce the workforce for an essential task in the hive. It is also wasteful killing the bees like this and not part of my beekeeping philosophy. As all other mite testing methods known in the field does not yield accurate mite levels. Sugar dusting is the kindest method. So recently, I stumbled upon the apiculture section of the Ministry of Agriculture and Lands of British Columbia website about varroa testing and I found the method that fits my style of beekeeping. Click here on Varroa Detection Method to reach the site.

Icing sugar method about 100-200 bees in the jar

The Icing sugar method requires a wide mouthed jar with the cap cut and a 1/8th wire mesh fitted onto the cut cap. I used a pickle jar and used a can opener to cut a large hole on the cap. I also bought a wire mesh colander from Daiso for $2. I cut the wire mesh out of the colander and there was enough mesh to create another 3 more testing jars. I used super glue to stick the wire mesh on the cap. Wait for it to dry for 15 mins and I got my wide mouth jar ready for varroa testing.

Find a frame with open brood with lots of nurse bees and be very sure that the queen is not on the frame. I think bees found on open brood frame is better for this method than bees on capped brood frames because the varroa mites attached on those bees are waiting for the opportunity to enter the brood comb before it gets capped to lay their eggs onto the bee larvae. The newly hatched varroa mite will then feed on the larvae. Therefore the infestation levels should be highest on frames with open brood as it has the best conditions for the varroa mite to continue its life cycle. After capturing enough bees about 100-300 or 1 cup of bees, cap the jar and sprinkle 2 tablespoons of powdered sugar through the wire mesh. I think even flour can be used, though I have not tried it yet. I took a video to show how I executed the testing method. I was really rough with the bees in the jar. Don't mind me. I feel bad myself but it is only to shake out all the varroa mite for an accurate count and to give the unlucky bees in the jar with varroa mites relieve once the mites gets detached. None of the bees died in this method. Even if some got injured and eventually died, it would be less than 10 compared to a 100% kill if using the alcohol wash. After shaking the sugar out of the jar, release the bees at the front of the hive entrance. Remember that nurse bees have never flown out of the hive before and may not know how to fly back to the hive if they get disoriented. So always return the bees as close to the hive as possible. Enjoy the video. The bees in the video are from Matilda.

I tested Bombay first and then Matilda. The results of the testing are

Bombay : 1 mite/100bees = Low infestation level
Matilda : 8 mites/100bees = High infestation level

Click on the picture for an enlargement. After all that shaking. The red/black specks are varroa. A white paper backing makes it easier to spot the red Varroa mites.

Was wondering why Matilda had such constant high infestation levels since last year. Even before I had problems with the queen. I am still wondering why. It is still too early for Queen Matilda II to correct this. It is just barely a month ago she took over from the drone laying queen. The drone laying queen has probably created the perfect condition for varroa mites to reproduce. Varroa mites love to lay their eggs and grow up with drone bees because the drone combs are more roomy due to the larger size of the drone compared to the tight comb of the worker bee and the pupae stage of the drone is longer than the worker bee by a couple of days. The extra days allow the baby varroa to feed on the host longer. Matilda definitely needs to be treated the 1st once the supers are off on Aug 15th.

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Read more on the Sugar Dusting Method: http://www.cals.ncsu.edu/entomology/apiculture/PDF%20files/2.03.pdf