Varroa mites bring disease and weaken the hives, which contributes to winter hive losses. Mite loads get highest in the fall and now is the time to treat the bees to get rid of the mites.
Here's the deal though - the chemicals used to kill the mites are really not all that great for the bees and generations of chemical treatments have selected for bees that don't do well without constant chemical intervention. We want to be as chemical free as possible, so we have a dilemma.
1. Treat the mites with traditional chemicals.
Con: Grow another generation of bees that can't survive without loads of chemical interventions.
Pro: It gets rid of the mites and prevents the spread of the diseases the mites carry.
2. Don't treat the mites.
Con: Risk losing the hives. It doesn't prevent the viruses, like DWV, that the mites carry.
Pro: This selects out the weak bees and selects for bees that can deal with a significant mite load. Bees that survive are the bees we want.
Basically, the choice was 'treat with chemicals' or 'don't treat at all'. In the past few years, beekeepers have discovered a 3rd option.
3. Treat the mites with powdered sugar.
Pro: The bees will groom the sugar off each other and knock off the majority of mites at the same time. Once the mites are off, they can't pass on a virus. The sugar also acts as food. If you sugar the bees in the fall, then they can store this food source for winter. Treatment without chemicals. It's a nice happy medium.
How to powder sugar the bees
You need about 1 cup of powdered sugar per hive. You also need some sort of fine screen to sift it through. You can use a real kitchen sifter, or strainer or something like that.
I used one of those flat round steamer/spatter preventers that we had in the cupboard as a sifter. [See top photo] I measured my powdered sugar in 8 oz jelly jars. All you have to do is turn the jar of sugar upside down and and rub it across the screen.
Open the hive and sift the sugar all over the frames. Make sure you put the sugar all over the hive.
I did smoke the girls a bit because it was a little breezy that day and even though I was working very quickly, they were unhappy about the disturbance.
Once you've sifted all the sugar into the hive, you can brush the tops of the frames to get that sugar down on the bees, too. I didn't bother.
I'll check them again during the January Thaw and put more candy in if they need it.