I have not heard about them for a while, but I think federations should be exclusive to human colonies, because the zolarg are insects who aren't as smart as humans, and the reptilians are too advanced to need them.
that wouldn't be fair. The point of the federations is so that commonwealths can help each other. Zolarg are smart, they are just a young race, and their technology is rudimentary but they can still travel the stars, otherwise they couldn't colonize other planets. Reptilians are very advanced, yes, but that still doesn't mean that their commonwealths won't ever need help from each other.
On a side note, would be nice to see organic space ships that the zolarg would use to travel in. They seem like they would grow giant living insectoid space ships that they could reside in and control. Perhaps the genetics tech would allow for a zolarg shipyard, where ships are genetically engineered and grown instead of built. The shipyard would consume sugar, water, and aluminum to grow the ships.