I have noticed recently that most of my Maples, and Callistimons have had leaves go brown and withered looking or just shortened

On Tuesday I took a tree to school and found some strange twig looking things on them and closer inspection ofound them to be long thin grubs that attach at both ends and camouflage themselves really well.
I have seen them before occasionally but this tree had quite a few on it.
Today I had a good look at all my trees and found hundreds of the buggers. Existing leaves have all been munched and are real paper thin and brown, and there is No new leaves on them at all.
Maples and Callistimons seem to be the targets only

I have picked them all off, and cut them in half

See the attached pics
Ken