hemipter vs true bug

hemipter

noun
  • Any organism of the order Hemiptera, including cicadas, aphids, planthoppers, leafhoppers, and shield bugs. 

true bug

noun
  • Any of various insects of the order Hemiptera and in particular of the suborder Heteroptera, that are wingless or have two pairs of wings, and have mouthparts adapted for piercing and sucking. 

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