Johnson, Susan ElaineI: The relictual reproductive soldier neotenics of primitive Termopsid termites may offer insights into the evolution of eusociality and sterile castes in termites. II: Soldiers and helpers in a new Thai species of Archotermopsis do not display unusually complete gonad development. The first neotenic pair ever reported for this genus is described. III: Morphological differences between soldiers and soldier neotenics in the head and gonads are quantified in Z. nevadensis. There is not necessarily a clear delineation in morphology between soldiers and soldier neotenics. IV: Colony age and size do not significantly influence the differentiation or survival of male replacement reproductives in colonies of Z. nevadensis. Soldier neotenics' development is not significantly influenced by the presence of normal soldiers. V: Soldier neotenics and related female neotenics tend to have greater initial survival after interactions with colonies with only normal neotenics. Mostly helpers are aggressors, never soldier neotenics or neotenics.en-USThesisBiology, EntomologyBiology, EcologyBiology, AnatomyArchotermopsiseusocialityreproductive soldiersoldier neotenictermiteZootermopsis