cockchafer vs green fruit beetle

cockchafer

noun
  • Any of the large European beetles from the genus Melolontha that are destructive to vegetation. 

  • Any of various other similar beetles, such as of the genera Acrossidius, Cyphochilus, Rhopaea, etc. 

green fruit beetle

noun
  • A beetle (Cotinis mutabilis) that ranges from central Texas across the southwestern United States and Mexico and feeds on cactus, desert trees, and cultivated fruit. 

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