reduviid vs big bedbug

reduviid and big bedbug both are nouns.

Word	Noun	Adjective	Verb	Adverb
reduviid	Yes	No	No	No
big bedbug	Yes	No	No	No

As nouns, big bedbug is a hyponym of reduviid; that is, big bedbug is a word with a more specific, narrower meaning than reduviid:

reduviid: a true bug: long-legged predacious bug living mostly on other insects; a few suck blood of mammals
big bedbug: large bloodsucking bug

Other hyponyms of reduviid include cone-nosed bug, conenose, conenose bug, kissing bug, Arilus cristatus, wheel bug.

reduviid (noun)	big bedbug (noun)
a true bug: long-legged predacious bug living mostly on other insects; a few suck blood of mammals	large bloodsucking bug