Field Guide to Moths of Eastern North AmericaBy Charles V. Covell, Jr.
Cite: 24520 with citation markup [cite:24520]
Treats 1300 species found in the eastern United States and Canada.
Covell's work has long been sought after, and his earlier guide has sold for over $100 in the used book market. Publication of this book puts him back in the affordable category!
Note, 7/18/2005: Amazon doesn't seem to list this book, but the Virginia Museum of Natural History says they have it and the price is $40.00.