That's what I meant. And it did move. This is a different bug. The other things sound like the gnats you were talking about.
Oh... I see. Very hard to tell, first impression is that it's a scale insect - but that's a really wild guess. It would be on the trunk, not in the soil, hardly visible, and if it is a scale bug, there are probably quite a few.
Let me know if that makes sense.