This was what I wanted to say in the original post -
I just noticed that ALL the citizens of my formerly human home world are now Festrons. The Festron civilization is not even in the game.
I am not disallowing foreign citizens on my planets. There are a few Drengins and others on some worlds. I guess the Festrons are like an "Invasion of the Body Snatchers" race that can turn other citizens into their own race, but, without checking all your planets every turn for a Festron "invasion", how can you know that a planet is infected. I would think that the governor would notice and be suitably alarmed. And, even if there was a notification, there should be some choice about how to stop it or let it continue.
I edited the original post with this information and pressed "submit changes" but it never posted it.