I also have quite a few whiteflies this year. There aren't enough yet to stress out my trees but I did a lot of research and didn't find anything that everyone agreed worked. Oddly enough, several people suggested supplimenting the soild with earthworm castings. Supposedly, something in the castings works as a natural systemic. I think I have plenty of earthworms so I am skeptical of that method. Neem oil and soap solution was another common remedy but several indicated that wasn't working very well for them. Everyone agrees you must treat the undersides of the leaves. Good luck and I'll be interested in what others have to contribute.

Your tree isn't an outside tree. It's an inside tree that vacations outdoors.

^^^very true.

regardless, it was after I put it outside it started the problem. Theoretically if the whiteflies can set that fast, the predatory bugs should come around too, but it's been a while and nothing yet. It's definitely not an "outside tree" but in the summer it is certainly a 'tree that is outside' and treated as an outdoor tree!

I think I got them!

I ordered horticultural oil, the "All Seasons" brand. I mixed 2 tablespoons into a quarter gallon spray bottle, shook it, and sprayed the everloving heck out of that tree, making sure to get the undersides of the leaves and the petioles and the branch junctions. I didn't spray the oil off, I let it sit till the next day, and sprayed it down yet again. The leaves were really slippery and oily (I kept it out of the sun for this) and I didn't spray it off the second time either. After the first time there was still tufts the next day, and after the second spray there was a stray one or two that I think were probably residual - but I sprayed a third time just to be sure. The day after the third spray there was no more sticky and no more fuzz, so I wiped the oil off with a wet sponge with a drop of dawn on it and wiped down the branches, etc. The shoots that just started were unharmed by all of this and are doing very well. The leaves were a little bit droopy from having oil coating them got a few days, but it's significantly perked up. Supposed to rain tonight, that'll wash off what's left.

So far, no tufts, no fuzz, no sticky. These next few days will be the tellers. I looked over my orange tree, which was showing the fuzzy signs of them, but it looks like they have abandon their try and the orange tree is as healthy as ever, save for some mild chlorosis from the constant rain and too much water (it is under shelter now). Still no new shoots from that orange tree, though.... I'm wondering about that. hmm.

So, if anyone else is having problems with them, while alcohol and neem didn't work for me, horticultural oil seems to have worked out great!