fruit fly vs louse

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". 

louse

noun
  • A small parasitic wingless insect of the order Psocodea. 

verb
  • To remove lice from; to delouse. 

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