My God, what an astouding idea! - Supa you are a genius!
Playing a game as a social insect - it does rock!
Really interesting and so informative discussion - I do like it

I never new much about arthropoda, nor their English names - it's great to learn new things
Now I can't wait for the MOD to be released!!! - Any coservative date?

))
As for the idea - I'd say that the concept of four generic types of social insects would do the best as each type civ could include multiple species with their respective units having specific features. Otherwise a single-species Civ would be way too-limited in terms of units and tech-tree.
The bees seem to be most restricted in this reguard and wasps do need to be included if one wants the Bee-civ to have any warrior unit at all (working bees do have modest defensive abilities but that about all...). And wasps are much more varied in size, life-strategies and apeearance - the wasp species array could make excellent source of various specialied and really deadly war-units in game (unlike mostly working-type bees).
And some wasp species are about the only insects that are naturally capable of surpressing the ever menacing unplayble Civ of the Arachnida...
The termites would make an excellent fortress-type defensive culture with units diffirentiated enough for any kind of needed tasks even within a single species - is that correct?
The Ants are a great kindom... absolutely shocking with their
real agricultural traditions like fungi-crop growing and aphis-herding.
- In my view, the ants should be the only creatures in the MOD to be allowed to have agriculture techs and irrigation abilities wich turns otherwise food-less terrain into fertile fungi plantations and boost the colony growth. It would be cool!
On the other hand, the Ants could be devided into two majour Civ-types:
1) "The Farmers" - at first relatively "cedementary" hunter-gather type of society like Formica rufus etc. with hunting\war units capably of long runs - and then this society gradually turns into a "hi-tech" Civ of agricultural ants (like those from the Bolivian rain-forests I forgot the name :-( ) -
2) "The Horde" - carnivorous all-devouring killing machine of nomadic Amazonian ants with billions of worker\warriors to crash everything in sight...
The Hord would need to be devoid of any food-providing resource (feature based on Tech-tree) except just some prey of VERY high appearance-disappearance ratio and - I'd say - provided with cheap settlers (no to let the Hord to die-off quickly when resource is suddenly gone).
WOW - I'd LOVE to play the mode!!! Especially if the overal graphic standards will remain as exceptionally high as in the units you've already presented, Supa!
What about tech-trees here - are there any formalized ideas?