Termite Colonies will often have a King, to some extent.  Instead of disappearing, and presumably dying after the nuptial flight, Termite Kings will stay with the Queen continuing to mate.  With each spawning of new eggs for the colony, the Queen becomes more fertile.  So the King in fact serves a valuable role in the preservation of the colony, as there is typically only one fertile male on hand at any given time.  In The Underground, Queen Rhi Mei of the Termite Union rules without her King, and thus she is visibly smaller when compared to the other Termite Queens.