Spanish fly vs love drug

Spanish fly

noun
  • A supposed aphrodisiac extracted from the beetle Lytta vesicatoria; cantharidin, the active ingredient, a vesicant used as a defence by L. vesicatoria and other blister beetles. 

  • The beetle Lytta vesicatoria. 

love drug

noun
  • The drug Viagra. 

  • The drug ecstasy. 

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