I never saw them again. I did as DSD recommended using alcohol and a Q-tip
on ones I saw. I've not seen any mature or brown scale either, but am having an issue
with all of my pine trees, 2 and 5 needle. A local agricultural extension agent was supposed to stop by and
take pics of them, but seemed less interested when he drove up and saw they were bonsai trees.
I had told him they were, but he didn't hear me I guess when I told him I was placing them down off the rail in anticipation
of wind gusts. They're susceptible to the same diseases as if in the ground I continued, but he didn't sound interested
in pursuing it any further.