H. umbrosaria is not easy to distinguish from H. gnophoraria. Genetalia dissection or antennal characters must be used (see Rindge 1973).
Wings of these species are light gray to medium gray or brown, with prominent discal dots forming round open circles.
H. Buchholzaria is also very similar in appearance to these two species, but its wings are dark gray, dark brown, or blackish, and have poorly defined lines. Also, it has not been collected very far inland.