cellar spider vs harvestman

cellar spider

noun
  • Pholcus phalangioides, a spider of the family Pholcidae. 

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 cellar spider and harvestman occurred in a corpus of books? (source: Google Ngram Viewer )