Further to replies about my strelizia suspected of having red spider mites

I don't think that is red spider mite. That usually occurs under the leaves with a definite fine webbing to see.
The mites themselves are hardly visible, not usually red until fully developed.
Someone else will have to tell you what that is

It could be sun scorch....even the most sun loving tropical plants will get scorched if not aclimatised properly.

yes, those red spider mites are easily identified by the fine web they spin all over the plant Sharon. I hope you get to the bottom of it soon!