bumblebee vs horsefly

bumblebee

noun
  • Any of several species of large bee in the genus Bombus 

  • A mid yellow 

horsefly

noun
  • Any of several medium to large flies, of the family Tabanidae, that suck the blood of mammals (not to be confused with Stomoxys calcitrans, the stable fly, or dog fly). 

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