If you can't see any bugs at all, then possibly watering is the problem - pines like to get pretty dry between waterings, and if your weather's been rainy, and the soil is not gritty and fast draining, that could be the answer. Did the 'garden' soil have lots of grit, sandy loam, etc. in there, or was it peaty, with possibly lots of clay?

It has been rainy lately. The garden soil was free draining originally, but in the course of the last 17 monthes it has become compacted and fairly slow draining. I plan to re-pot in spring, would it be a good idea to re-pot now, with frost this weekend and freezes about a month away?

Actually, not at this point, just don't water any more, or only if things end up being so dry most of its soil dries out, but that seems pretty unlikely. You need more info. long term tho', so www.evergreengardenworks.com/articles will take you to a great website for lots of bonsai stuff, and excellent info on blk. pines.

There is a possibility that you have a bug. I cannot now remember the official name for the thing but it bores into the buds of pines and lays an egg or two. Remove one of the affected buds and carefully pull it apart to see if you can find the offending little creature. Sometimes you can actually find the hole drilled into the bud if you look carefully.

If you do it is recommended that your remove all of the affected growth down to healthy needles. This will of course cause a lot of back budding in the spring