My citrus was affected by frost this season but however at the start of spring it started to bloom and had new growth. But for past 3 weeks I have started t o see new leaves starting to die and the branches turning brown.
I applied insecticide but haven't seen any effect yet.
The attached photo is of a orange tree. I also have a myers lemon which is showing the same problem.
Is it any disease that I am looking at or a insect problem?

Any help appreciated

Thanks

decks