I call it white fly or lace bug... Bonide should help. I have also used malathion for a more immediate result. It usually takes several applications to get them all. Leaves are permanently damaged. It will take at least two years to get all healthy foliage again. You need to watch when you water...if you see small white bugs flying up from the trees it is time to investigate. If it seems like they won't go away check any shrubs in the landscape for infections and treat those as well. Very unsightly but can usually be brought under control with a little effort.