cockchafer vs green June beetle

cockchafer

noun
  • Any of various other similar beetles, such as of the genera Acrossidius, Cyphochilus, Rhopaea, etc. 

  • Any of the large European beetles from the genus Melolontha that are destructive to vegetation. 

green June beetle

noun
  • Cotinis nitida, a species of beetle found in the eastern United States and Canada. 

How often have the words cockchafer and green June beetle occurred in a corpus of books? (source: Google Ngram Viewer )