A planet whose civilisation fell to the flying neural parasites two years before they reached Deneva, forming part of the trail of mass insanity traced in Operation: Annihilate!
Ingraham B is mentioned in the Original Series episode Operation: Annihilate! Spock and Kirk are following a line of worlds on which whole populations went mad, one after another, over a period of centuries. The pattern runs through the ancient civilisations of the Beta Portolan system, then Levinius V two hundred years ago, then Theta Cygni XII, and reached Ingraham B only two years before the events of the episode.
The next planet along the line is Deneva, home to about a million colonists, among them Kirk's brother Sam and his family. The Enterprise arrives too late to prevent the infestation.
The cause is a swarm of single-celled creatures that fasten onto the nervous system and rule their hosts through pain. Ultraviolet light from orbiting satellites finally kills them on Deneva.