Thanks for your comments. I'll go with Hypagyrtis unipunctata unless someone comes along stating otherwise.

...but that lighter median area makes this a One-spotted Variant in my book. Esthers tend to have darker brown beyond the pm. line and a lighter brown where this one is more white. Problem is, even with Bob Belmont's Hypagyrtis Variants page at MPG, it would take even more photos of authenticated material to clearly delineate where overlaps between the species begin and end. So, even though I'd file it under H. unipuncta, I could very well be wrong.