Thanks for your replies. In answer to your questions:

1. I haven't had the tree very long. Perhaps about 2 months. I just repotted in a few weeks ago and I wonder if these bugs were in the soil or something because I didn't have this problem before.

2. THe bugs are very small. In fact, I didn't notice them at first. But the white, sticky fluid does seem to be coming from where the bugs have done damage. After posting this message, I looked closer at the tree and noticed that there were some bugs on the leaves as well as the branches. And there are also problems with peeling bark as well as small black spots on the leaves.

I went to the garden shop a few days ago. But they didn't know what insecticidal soap was. In fact, they didn't know alot about bonsais, and reccommended an insecticide spray for house plants. I have used it once and it seems to have worked since I haven't seen any of them lately. The active ingredients are: Bifenthrine and Propiconazole.

I also have two other Carmosa bonsais and I am wondering if I should treat them for bugs as well, although I've seen no sign of the same kind of pest on these trees. I did use the same soil when repotting them.

I hope this will help to identify the bug because I'd really like to know what it is!