deer fly vs deer ked

deer fly

noun
  • A Eurasian species of louse fly in the family Hippoboscidae, Lipoptena cervi; parasites of elk, deer and other bovine animals, sucking blood and laying eggs in the fur of the host animals. 

  • A gold- or green-eyed horsefly of the genus Chrysops in the family Tabanidae; pests to cattle, horses and humans, feeding on their blood. 

deer ked

noun
  • A Eurasian species of louse fly in the family Hippoboscidae, Lipoptena cervi, that are parasites of elk, deer and other bovine animals, sucking blood and laying eggs in the fur of the host animals. 

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