My educated guess is that the winged insect is feeding on the 'honeydew' residue from the scale insect, or on the scale itself. It isn't part of the problem; just an opportunistic feeder.
Missed your post, sorry. The honeydew residue explains a lot, last night I just couldn’t see the little buggers in it. I’m curious what these other bugs are because they are all over the weeping maples too. Called the VA Ext CoOp and they haven’t returned my call. Guess I’ll check with the arborist link you gave me.
Success!
http://www.goodtreecare.com/find-an-arborist/va/fairfax