green lacewing vs lacewing fly

green lacewing and lacewing fly both are nouns.

Word	Noun	Adjective	Verb	Adverb
green lacewing	Yes	No	No	No
lacewing fly	Yes	No	No	No

As nouns, lacewing fly is a hypernym of green lacewing; that is, lacewing fly is a word with a broader meaning than green lacewing:

green lacewing: pale green unpleasant-smelling lacewing fly having carnivorous larvae
lacewing fly: any of two families of insects with gauzy wings (Chrysopidae and Hemerobiidae); larvae feed on insect pests such as aphids

Other hypernyms of green lacewing include lacewing.

green lacewing (noun)	lacewing fly (noun)
pale green unpleasant-smelling lacewing fly having carnivorous larvae	any of two families of insects with gauzy wings (Chrysopidae and Hemerobiidae); larvae feed on insect pests such as aphids