Il Neo (La Mouche) is an opera in 1 act, 3 tableaux (novelletta musicale in 3 piccoli quadri — musical novelette in 3 little tableaux) by Henrique Oswald to an Italian libretto by after a novella La mouche by Alfred de Musset. Composed in 1900. Never published, It is the only of three operas by Oswald which definitely was staged.