aphid vs harvestman

aphid

noun
  • Sapsucking pest insect of the superfamily Aphidoidea; an aphidian. 

harvestman

noun
  • An order of terrestrial, non-venomous arachnids with often very long legs: Opiliones. 

  • A field-worker who works to gather in the harvest. 

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