deer ked vs horsefly

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. 

horsefly

noun
  • Any of several medium to large flies, of the family Tabanidae, that suck the blood of mammals (not to be confused with Stomoxys calcitrans, the stable fly, or dog fly). 

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