damselfly vs dragonfly

damselfly

noun
  • Any of various insects of the suborder Zygoptera that have long slender bodies, and are similar to dragonflies but having wings folded when at rest. 

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. 

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