cockchafer vs cockroach

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. 

cockroach

noun
  • A black or brown straight-winged insect of the order Blattodea. 

  • A Tutsi. 

  • A person from New South Wales. 

  • A person or a member of a group of people regarded as undesirable and rapidly procreating. 

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