harvest mite vs redbug

harvest mite

noun
  • Any of various mites of the genus Trombicula that inhabit forests and grasslands and which, in their larval stage, attach to various animals including humans and feed on skin, often causing itching. 

redbug

noun
  • A particular kind of insect, a member of the family Pyrrhocoridae. 

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