Identification
Adult: has several named forms whose forewing color varies from grayish-brown to completely black; forewing usually with some whitish in median area; reniform spot usually outlined with white (or solid white in form "conspicua"); AM line broad, black, and relatively straight, contrasting against paler median area; hindwing median band reddish-orange or dark pink with deep scallops near anal angle; sometimes rests with wings partly open, revealing parts of two colored bands and two black bands; fringe pale orangish, narrow except at apex.
Per Wagner (2005), most caterpillars are gray and essentially bark-colored, but
very occasionally
spectacular lichen mimics are encountered.
(2) Examples of each larval form:

,

Range
eastern and central North America: Newfoundland to Florida, west to Texas, north to Saskatchewan (plus two recent records from California, 1999 and 2004, reported in
Lepidopterists Society Season Summary)
Season
adults fly June-September
Food
Larvae feed on leaves of oak
Remarks
Per Wagner (2005), this is
one of the East's most abundant underwings. (2)See Also
Catocala umbrosa forewing lacks conspicuous white outline around reniform spot (
compare images of both species at CBIF)
Print References
Covell's Field Guide to Moths of Eastern North America, page 307 (2005 edition)
(1)
National Audubon Society Field Guide to Insects and Spiders
(3)Internet References
Moth Photographers Group - range map, photos of living and pinned adults.
The Catocala Web Site many live images of all life stages plus description, distribution, flight season, foodplants, biology (Bill Oehlke, silkmoths.bizland.com)
MIACY live adult image (John Himmelman, Connecticut)
Maryland Moths live adult images plus flight season and foodplant (Larry Line, Maryland)