You are probably watering too often (which is more important than too 'much' at any given time) and the soil should probably be scrapped in favor of some with a lot more grit in it allowing water to drain quickly (and never leave the pot sitting in drain water, but raise it on pebbles to help humidity). The bugs have no business there whatever they are so I suggest you get the tree out of the pot (over a big sink) and wash all the soil away - after having picked up a small bag of small sized aquarium gravel, with some perlite mixed in and some 'porous' (ask for it) at a garden centre - vs potting soil that has too much peat in it. Mix it all up when you repot, don't cut any roots now or use fert. or hormone powder, but do try to acquire better lighting (T5 fluorescents 5-6 inches over the tree x 15 hrs/day will do - a small fixture for now is still the least expensive way to go - 'grow' lites aren't generally that much good. Use a little fungicide according to label info. in the first water after repotting and relax - serissas can make you crazy, but if you leave it alone a bit more and just let it be between waterings, it can recover, though may be weeks.

Any suggestions on how to re-pot the tree? I think that the pot I have it in now is too big. When I was given the tree as a gift- it was placed in pot that looks like it would have been good for a small flower- ie its plastic, green, circular and pretty tall for such a tiny tree. My little tree seems pretty young- how deep of a pot do I want to get for it? So you would suggest not buying some bonsai potting soil? Would you recommend soaking the pot in water before replanting the tree so that the soil is moist? I've been watering the little guy about once a week- but perhaps I've been using too much water and I've also used tap water which I just discovered is apparently a big no-no. Would you recommend putting the plant outside at all for some natural light and humidity? Additionally do these types of trees need humidity trays? Sorry I'm rather new at this and told they were easy trees to take care of. I'm learning that they're a lot more work than I thought!

You have a lot of bad info. it seems. Tap water is just fine unless you know for a fact that yours is particularly full of something bad (like salt, if the water comes from a water conditioner that isn't a reverse osmosis type). No you should not soak the pot prior to repotting. No you should not be watering once a week or a day or on Tuesdays, but when the tree needs, and that's something you have to learn - but common sense says the soil shouldn't be sodden all the time, nor completely dry, but somewhat moist throughout, though the top can be dry if the plant doesn't complain. Again, soil mix is very important and what is sometimes sold as 'bonsai' soil isn't always much good. Yes a humidity tray is important. Water slowly and well when the repot is overwith. Don't think about 'bonsai' pots right now - in fact a slightly larger one (for a year or two) may be good for development and a small one with restrict that. Go to www.bonsai4me.com and get more general info. on growing bonsai and try to pick up some books - however, right now your concern should be keeping it alive and not styling it... that can wait.