(Found) looking for the title of a book that featured sentient beetles and cat people

[skaboy1983]

I read a lot of sci -fi in the 80's and 90's.and I would like to find a book I read back then. It mainly dealt with humans (Chinese if I remember rightly) who controlled 'chitin' which prolonged life and was only available on a planet which had huge trees where the beetle colonies (which produced the 'chitin') dwelt. Also the indigineous species of the planet was human shaped felines. I seem to remember at the end, the trees lit up as they were part sentient, and this expelled the humans. Hope someone remembers this novel. (thinking again it may have been a trilogy) Thank you

 

[Danny McG]

This is The War for Eternity by Christopher Rowley - part of a 4 book series.
The natives were more bearlike than catlike.

The 'blurb'....
A World Under Attack!
The bearlike aliens of Fenrille had long been allies of the fiercely independent human clans. Together Men and Fein ruled the wooded highlands of the odd planet's single continent.
And together they grew rich, for only the people of the highlands could harvest the drug that kept men forever young.
Then the masters of a distant Earth sent a Starfleet with a force of brutal Space Marines to seize the planet. But they weren't prepared for the colonists' stiff resistance-and no one had warned them of the alien's very special defenses

 

[skaboy1983]

That's the book Thank you for your help