bedbug vs insect

bedbug

noun
  • A small nocturnal insect (Cimex lectularius), of the family Cimicidae, that feeds on the blood of humans and other warm-blooded hosts. 

insect

noun
  • Any small arthropod similar to an insect, including spiders, centipedes, millipedes, etc. 

  • An arthropod (in the Insecta class) characterized by six legs, up to four wings, and a chitinous exoskeleton. 

  • A contemptible or powerless person. 

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