It sounds like your ficus are very important to you, and I can understand why. I truly recommend a professional pest management team resolve your issues here.
The most natural way we control these pests is with Pyrethrum (chrysanthemums) based insecticides, with stickers. Stickers allow the insecticide to remain on the surface. There are some systemic insecticides that are absorbed into the plant/tree, so when insects chew they consume insecticide.
There are many factors when dealing with these pests, and the pros know all of them. Natural remedies can work if you find the right one in time to save your plant/tree! Time is of the essence here. Time is your enemy, and if you want to make sure you save your plant/tree, taking chances with home remedies is taking a chance that you will lose the plant/tree. My advise here is at least have a pro look at it for you. Most reputable pest control pros also guarantee the application.
Hope that helps!
Have a pest free day!
http://www.newerapestcontrol.com
