insect girdling Ficus benjamina
The insect looks a cross between scale, mealy bugs, and fungus. It is under the bark at branch joints and has girdled the top-most branch of an eight-foot ficus I've owned 23 years. The tree was outside under a pinyon pine last summer. There is no observable honey dew, no sooty mold, no bodies on leaves. Leaves are clean and green until they dry and fall from affected branches. The puffy scale-shapes are approximately 1 millimeter, white with orange dot and have cotton-fiber appearance.
I repotted the tree, removing most soil from the roots when I brought it inside end of September. It liked out-door living and rebounded from two years of leaf drop. The leaf drop coincided with installation of low-e windows.
Arapahoe County Colorado trees and shrubs
Would it be possible to send a picture of your Ficus tree showing the areas you are describing? It would be very helpful in trying to diagnose this issue. Thank you.