A significant white spot on the head (2005 photo) is, according to Covell, a characteristic mark of 5166 - Desmia maculalis. Brian Scholtens informs me that this is not a reliable character and that the two species cannot be distinguished in typical dorsal view photos. It would be necessary to see mouth parts at high magnification or examine genitalia to make specific determinations. It is best to consider photos of these species as representing a species group.