cockroach vs fruit fly

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. 

fruit fly

noun
  • any insect of the Tephritidae family, whose larvae damage plant tissue. 

  • any insect of the Drosophilidae family, whose larvae feed on ripening fruit, especially the species Drosophila melanogaster that is used in genetic research. 

  • A woman who enjoys the company of homosexual men; a "fag hag". 

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