Other Common Names
larva known as Saddleback Looper (forestpests.org
Synonyms and other taxonomic changes
Ectropis crepuscularia ([Denis & Schiffermüller], 1775)
Explanation of Names
CREPUSCULARIA: from the Latin "crepusculum" - twilight
crepuscular animals are most active during twilight (dusk and dawn), whereas nocturnal animals are most active during the night, and diurnal ones during the day
Ectropis crepuscularia is the only member of the genus in America north of Mexico.
small black dentate (tooth-like) markings along 3 or 4 lines that cross the wing
amount of dark banding varies from heavy to almost none, but the darkest mark on the forewing is a blackish blotch along the postmedian (PM) line near the center of the wing - distinguishing this species from Protoboarmia porcelaria
(Porcelain Gray), whose darkest mark is at the costa where the PM line begins
E. crepuscularia lacks a short dark streak just below the point where the antemedian (AM) line touches the costa, and usually lacks a dark spot near the middle of the hindwing (both of these marks are present in Protoboarmia porcelaria)
Some of the various forms:
Coast to coast in North America, north to the panhandle of Alaska
but not Yukon or NWT
also occurs throughout Eurasia
The main flight period appears to be March to October.
The larvae present in July and August in northern US and southern Canada.
The larvae are generalist feeders on balsam fir, hemlock, larch, cedar, spruce, apple, alder, birch, elm, maple, oak, poplar, and willow.
One generation in the north; 2 or 3 in the south.
Larva, Mating Pair:
(both genders with simple antennae)
Protoboarmia porcelaria (Porcelain Gray) which is smaller and has a short dark streak just below the point where the antemedian (AM) line touches the costa. See comparison images
of both species.
Powell, J.A. & P.A. Opler, 2009. Moths of Western North America
. University of California Press, p. 210; plate 28, fig. 17. (1)
live adult image
(Esko Viitanen, Finland)
live larva image
plus text description and other info (forestpests.org)
pinned adult image
(James Adams, Dalton State College, Georgia)