Very similar to the other two species of Eufidonia, and best separated by genitalia (Rindge 1990, McGuffin 1981). E. convergaria was formerly considered to be part of notataria. This was changed by McGuffin (1981).
This species and convergaria are slightly larger than discopiliata (McGuffin 1981).
The only reason I didn't lump discopiliaria into this species complex is because it is smaller, usually has more sharply defined lines and a more black/gray rather than brown/red coloration. None of these characters would be distinctive by itself.
McGuffin lists the wing expanse of discopiliata as 18-22mm, compared to 22-27mm for the other species.
Distribution pattern: Northern. The ranges of all 3 Eufidonia species overlap almost entirely.