Taking over a planet

Destroying the planet is the only way.

Bomb them back to the stoneage.

The Vasari are a proud people and will never bend knee to some lesser life form like TEC members.

Luckily, your capital ships have big missile launchers for just that sort of problem. (The Marza's Raze Planet ability also does a really good job of wiping people out after you get it upgraded.)

You can also destroy with culture! I am note sure if this is ironic

You either overpower their culture until they go neutral and you can colonize, or blast them into oblivion and colonize. Either way is good, but I like seeing the sweet explosions!

Thanks to all. I am convalescing after pneumonia and this is really getting my brain (and lungs) working again. I can see me playing this for weeks to come.

Filthy Human. We were traveling the stars when your ancestors were still swinging through trees! You expect us to surrender a resource colony to a monkey?!!

Your species is amusing, and we'll be certain to keep a few examples of it alive for bestiaries abourd our Jarrasul class world ships. Contrary to your foolish beliefs, our species does not trouble ourselves with living in wild gravity wells, we occasionally step foot upon such primitive regions for entertainment such as hunting, or to ensure the proper management of our labor colonies, however we've no desire to actually LIVE on a planet, the very idea is abhorrent!

No, we merely subvert enough of the native species using simple bionic neural implants to ensure a steady output of resources.

You have to bomb the planet.I like using that big cannon that you have to research!