cockchafer vs coprophagan

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. 

coprophagan

noun
  • Any of a number of beetles that feeds on dung. 

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