25 Dec 2014 - Mike Quinn, Texas entomologist and author of the most authoritative WW info source on the web, suggested I post to the Mariposas Mexicanas Facebook page. MMigue Hdez relates that black witch (Ascalapha odorata) is common in Chiapas (Mex), and that he has twice observed WW. Juan Carlos Garcia Morales says that he knows of white witches in Chimalapas, Oaxaca (Mex). The white which is known there as "la gavilana" (the hawk) though the flight is more owl-like. --DLC
21 Dec 2014 - I've begun to look for museum records online, starting with the 50 or so links on the museum list at the Entomological Society of America. Fantasy: there will be a photo-referenced www accessible database for most of the many million specimens held in prominent university collections. Not so. Most museums are not searchable, though there is a meta-database (SCAN) representing (at least parts of) 23 collections.
I found 14 records for T. agrippina, 10 for T. zenobia, 129 for A. odorata. Most records are sadly incomplete (must be more data on the physical labels), though one JO Prosek helpfully noted specific locality and elevation for his black witch. --DLC