I have a couple of jade and dwarf jades on my windowsill, and I think they've been infested with mealy bugs - I had an infestation about a year ago, on a different plant, and I think it spread to the jades.
The mealy bugs have spread to a couple of plants, but on most of them I spray with water and dish soap and it seems to have killed all of them. But on the jades on the window sill, it looks like ants are tending the mealy bugs, and because the jade's leaves are so close together, I can't really get at them with the dish-soap-and-water spray like I could on the other plants. What do you do in such cases?
Also, I have to say, I'm worried that what I have might not even be mealy bugs- I've included a few pictures, so tell me if it's something else that just happens to be white and similar-looking. I'll try to add better pictures as soon as I succeed in getting them in focus.
This picture is of the jade, with what I think are the mealy bugs hiding in between the leaves (it got worse when they flowered):
This picture is of a different plant (I don't know what it's called) in which the same pest appears only sporadically and can be more-or-less controlled by a soap-and-water spray. You can see one in the very center:
Here's another shot of a jade with them on it. You can see the ones that are exposed, on the leaves, but there are more beneath those which are the ones I've been having trouble with.