lovebug vs sugar beet

lovebug

noun
  • A person who is in love; a sweetheart. 

  • An insect, the honeymoon fly (Plecia nearctica, family Biblionidae). 

sugar beet

noun
  • darling; sweetheart 

  • A type of beet whose root contains a high concentration of sucrose. 

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