This appears to be the White Flatid Planthopper. Or a close relative. The nymphs are extremely fluffy little puff balls. And many of them cover their eggs with fluff.

I'd use some insecticidal soap for these guys. Plain water might not get through the fluff.

Thanks, rhizo, your ID looks correct. I may have waited too long though. Most of the fluff is gone now. Some of the planthoppers are looking brown and diseased.