dragonfly vs katydid

dragonfly

noun
  • An insect of the suborder Epiprocta or, more strictly, the infraorder Anisoptera, having four long transparent wings held perpendicular to a long body when perched. 

katydid

noun
  • A relative of grasshoppers and crickets, in the family Tettigoniidae. 

How often have the words dragonfly and katydid occurred in a corpus of books? (source: Google Ngram Viewer )