acarid vs mite

acarid and mite both are nouns.

Word	Noun	Adjective	Verb	Adverb
acarid	Yes	No	No	No
mite	Yes	No	No	No

As nouns, mite is a hypernym of acarid; that is, mite is a word with a broader meaning than acarid:

acarid: very small free-living arachnid that is parasitic on animals or plants; related to ticks
mite: any of numerous very small to minute arachnids often infesting animals or plants or stored foods

acarid (noun)	mite (noun)
very small free-living arachnid that is parasitic on animals or plants; related to ticks	any of numerous very small to minute arachnids often infesting animals or plants or stored foods
	a slight but appreciable amount