dung beetle vs green June beetle

dung beetle

noun
  • Any of the true dung beetles of subfamily Scarabaeinae. 

  • Any of the beetle of the family Scarabaeidae (scarab beetles), especially of the subfamilies Scarabaeinae and Aphodiinae, noted for rolling dung into balls for use as food or as brooding chambers. 

green June beetle

noun
  • Cotinis nitida, a species of beetle found in the eastern United States and Canada. 

How often have the words dung beetle and green June beetle occurred in a corpus of books? (source: Google Ngram Viewer )