How do primary endosymbionts of insects differ from secondary endosymbionts?

Question

Quizplus · Accepted Answer

Primary endosymbionts have co-evolved with the host insect for millions of years and are essential for the insect's survival by producing vital nutrients. Secondary endosymbionts are not as essential and vary in their relationship with the host, often not remaining with the host after a few generations. Primary endosymbionts show evidence of co-speciation with the host insect while this is not common in secondary endosymbionts.

How Do Primary Endosymbionts of Insects Differ from Secondary Endosymbionts