This afternoon during a hive inspection I noticed what looked like a white powdery substance on many of the frames and capped honey in my two hives - almost looks like a mildew of sorts. It's pretty tightly adhered to the frames and comb and really doesn't come off. Otherwise the hives seemed pretty healthy. The last time I was in the hives was about a month ago and, at that time, I saw no sign of this substance.
I've been feeding the bees 2:1 sugar syrup with fumagillan and honey-b-healthy for the past two weeks. Perhaps what I'm seeing is just some residue?
I just want to make sure this isn't some sort of issue that requires treatment.