I suspect that you already know this, but I use a mixture of dish soap, vegetable oil, and a little bit of isopropyl alcohol for my indoor plants when I don't want to smell fish oil (my outdoor mix) in the winter.

The recipe is approximately as follows
1 L water
1-2 tablespoons of vegetable oil (sorry on units)
1 table spoon dish soap
Approximately 5 mL alcohol

This seems to at least keep them at bay until it gets nice out.

By the dish soap do you mean just a normal bathroom kind of soap bar (not perfumed not fragranced, just kind, as the ad goes?). I had heard the oil, water alchohol before, but had not had the soap as an emulsifier before.
Thanks for your help?
Gareth

Dish soap=washing up liquid
The kind from the kitchen sink

If you have the time and patience the achohol and a q-tip will do the job. But, if you miss one they will be back. I suggest the systemic. In your closed environment, once you stop them you should be fine.

Vernon

Kill them all. Quarantine the plant if not done already. Send those vile pests back to the dark, cold holes from which they are born. I use the systemic twice as strong on ficus just because I know they can handle it and spring back. Wouldn't recommend that for a fukien. How long have you had the tree? I had trouble growing one indoors all the time. I think they are slighly difficult and sensitive.