Drosophila melanogaster vs drosophila

Drosophila melanogaster and drosophila both are nouns.

Word	Noun	Adjective	Verb	Adverb
Drosophila melanogaster	Yes	No	No	No
drosophila	Yes	No	No	No

As nouns, Drosophila melanogaster and drosophila are synonyms defined as:

Drosophila melanogaster and drosophila: small fruit fly used by Thomas Hunt Morgan in studying basic mechanisms of inheritance

Drosophila melanogaster (noun)	drosophila (noun)
small fruit fly used by Thomas Hunt Morgan in studying basic mechanisms of inheritance	small fruit fly used by Thomas Hunt Morgan in studying basic mechanisms of inheritance