This is the first year (of 20) that I have seen this on our apple tree. Noticed first on water sprouts that grew from roots near trunk. One sprout looked like it had been dusted with white cotton candy from the tip to halfway down the sprout. Cut the sprouts and discarded them far away from tree. Tonight noticed several small tufty bits near the end of a couple of branches. Picture enclosed. Any idea whether this is an insect or a fungus - and how to best treat it?