Varroa and powdered sugar

Can someone explain to me why powdered sugar works as a treatment for varroa?

It doesn’t make sense in my head how this would be effective at all? Do the fine particles suffocate the mites like birds taking a dust bath? Does it cause the bees to be more hygienic making them knocking them off while they clean the sugar off of their bodies?

I see this method mentioned all over the place but only people saying “Do this”, not “Here is why you do this”. I am one of those people who has to know why I am doing something before I do it.


It doesn’t.
What’s more, too liberal application damages open brood.

Some say that bees are losing the hygienic behaviour because they are treated with various chemicals. I’m lucky “Touch wood” I have no Verroa - I check and clean my board weekly. I only find wax trimmings, occasional legs, pollen and various other hive detritus and one or 2 ants.

The Icing sugar will not harm the bees per see but will encourage grooming and in doing so the Varroa will fall off or be knocked off and through the Varroa screen onto oil - I lightly oil my boards.

It used to be 5 Verroa to 100 Bees but now they say that is too many and the count should be 3 Verroa to 100 bees.

If you are treating for Varroa August/September is the time after the Honey is extracted - making sure there is enough supplies to get the bees through winter. Once treated for Varroa you cannot extract the honey as it taints it and is in edible. Read the directions on the chosen treatment.

Any inert dust will interfere with the mites’ ability to hold on to the bee plus it sets off grooming behavior in the bees. Look up research by Nicholas Aliano.

People have used lots of things to get bees to groom and knock off the varroa. Some people sprinkle dry road dust on them…or icing sugar. There are Bee Gyms which bees will rub against…or a CD disc with grit on it for them to rub off the varroa. All work somewhat…whether sufficiently…who knows. If the colony is strong they do cope with varroa but there is no doubt that it does weaken the bees if there is a heavy infestation…and can be a cause of colony loss during the winter.
I use a sublimator with Oxalic Acid…(Rhubard juice crystals). It’s easy to do…you don’t have to open the hive. I would only treat if it is indicated. I monitor the natural varroa drop and do sugar rolls to find the supposed varroa load. If it is exceptionally high…I would treat. Luckily my bees don’t seem to carry many varroa since I sublimated last year. The worrying thing for me is not so much the varroa but the virus and disease they carry.

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It depends what you use.
MAQS is best used earlier in the season with honey supers on.
Oxalic sublimation doesn’t affect the honey either. It’s what I use and as horsehillhoney says…you don’t even have to open the hive.
BTW natural mite drop is no indication of the infestation in the hive. For this you have to sugar roll or alcohol wash

I am sure there are some varroa on your bees…they are endemic here in the UK. Although the numbers may be low.

A general rule is that if you keep bees in an area where Varroa are present, you have Varroa in your hive whether you see them or not. In regard to treating, I do nothing but increase from my strong colonies and let weak colonies fail.


What’s the most common path of transmission if you start with a hive and bees that are free of verroa or is that a fallacy, do all bees have verroa you just cant see it due to the number of bee bodies.

Bees will pick up varroa when they are out foraging…they meet with other bees. Also drones visit other hives and bring them back.
I use sublimated Oxalic acid…3 treatments 5 dYs apart…that will get the varroa which hide in the cells. However, I don’t treat unless there is a real need to do so.
I am slowly moving towards a no treatment regime.

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Wow new information to learn. I’m use mite strip. Its trap varroa.