inchworm vs looper caterpillar

inchworm

noun
  • The larva of a moth of the family Geometridae. 

verb
  • To move in a looping fashion, like an inchworm. 

  • To crawl or creep slowly. 

looper caterpillar

noun
  • The larva of any species of geometer moths (and of some species of noctuid moths) that moves with a looping gait, such as the cabbage looper. 

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