I realised that from referring to the better images on your website that E. ignealis is strongly sexually dimorphic which was also borne out by reference to the images for the species that are the ALA webpage. I could see that E. ignealis males were similar looking to E. mesentarialis, but that in E. ignealis of both sexes the outer subterminal band is wavy in shape (more easily seen in the males) and is at a greater distance from the termen of the forewing in E. ignealis than in E. mesentarialis. Futrther, there sems to be a small black (and white) spot near the forewing wingtip in E. mesenterialis which seems to be missing (or much less pronounced) in E. ignealis. Anyway, that's the rationale I used.