Apparently Terry Matalas considered it but went with the Changelings instead:

> I do like the conspiracy bugs, I did consider for a hot minute, the conspiracy bugs. The issue with the conspiracy bugs is they kill their host. So that would mean anyone that you saw with a bug in them was dead, and you wouldn't be able to do the paranoia thriller that you wanted to do if it was somebody you loved, that meant they were dead. So there [were] about three storylines I couldn't do without killing legacy characters.