I don't know how to distinguish Ardozyga catarrhacta from A. mesochra. ANIC has the ACT specimens under mesochra, although both species are apparently widespread.
Hmm, yes. In response to your doubt I had a look at the posted ALA specimens of both these species. I thought perhaps A. mesochra could be different to A. catarrhacta in that the central black marking might include the terminal apex of the forewing. This seemed to hold good for the posted A catarrhacta speciemens, but not for one posted A mesochra specimen. I note also that P. Marriott posted a very different looking elongated Ardozyga sp. amongst the A. mesochra postings. I couldn't find any observational notes for any of the ALA Ardozyga specimens of these species suggesting how to tell the difference.