I did it for the first time last weekend ,with a very light sprinkle from a flour sifter, had normally a varroa drop of 5 to 10 per week,
dusting knocked off 20 in 15 minutes and a futher 20 by next days
why did i dust well a friends hives not treated with oxalic last winter dropped 500 in the first 15 minutes when dusted by the SBI who diagnosed Defromed wing syndrom
iwould not use it regulary, as icing sugar and brood jeely does not go well and set like concrete
does it work as a varroa control, i doubt it as only 20% of varroa are out of brood cells in any one day