Identification
Adult: forewing bicolored - trailing half and outer edge mostly dark reddish-brown, and leading half mostly gray; orbicular spot indicated by a rusty streak, and reniform spot by a thin vertical rusty line; basal area has two blackish-brown streaks (giving rise to the common name); male has prominent dark "tooth" on inner margin halfway between base and anal angle
female hindwing dark reddish-brown; male hindwing white with dark anal mark
Larva: outline unique with backward projecting, fleshy humps on second and third abdominal segments; raised angulate eighth abdominal segment; head with front flattened, slightly lobed to either side, festooned with black spots, and pale line running from antenna to vertex; oblique lines to either side of midline on midabdominal segments (description from Caterpillars of Eastern Forests)
Range
southern Canada and northern US east of the Rockies: Alberta to Newfoundland, south to Colorado and Pennsylvania (see
distribution map at MPG)
Habitat
deciduous and mixed woods and shrublands
Season
adults fly in June and July
larvae from July to September
Food
larvae feed on leaves of poplar and willow
Life Cycle
one generation per year, with a partial second generation in some areas
See Also
a similar species (
N. pacifica) replaces this one west of the Rockies
