I don't believe in symbiosis. That's why I had all my mitochondria (and bacteria) removed.
If the insects find a way to incorporate some of the bacterial DNA into their own DNA then genetic evolution will have taken place. I think symbiotic evolution such as with mitochondria and chloroplasts is a lot rarer. Those are the only two examples that come to mind.
"Necessity is the mother of invention" is a silly proverb. "Necessity is the mother of futile dodges" is much nearer the truth. -- Alfred North Whitehead