Unless you have another Pokemon with strong attacks like Psychic, Air Slash, Giga Drain etc with high Special attack( i.e. a good special sweeper with good coverage), yes.
What I mean is, Mothim is an OK (bordering to good) choice for Special coverage sweeping. With the right EV's, Mothim can just own. If you already have another Pokemon for that purposes, no point keeping both Mothim and Staraptor. Staraptor is physical beast, while is quite good(if used properly) as a special attacker.
In short, I think, yes.