Other Common Names
Greenstriped Forest Looper (larva)
Identification
Adult: forewing light to medium brown with dark brown speckling; PM line scalloped, prominent; median and AM lines usually fainter; ST line composed of several black spots; discal spot small, round, black
hindwing similar but slightly paler and with slightly scalloped outer margin; markings faded/absent along costal margin
Specimens identified by DNA analysis:
Larva: head unmarked green; body green with broad whitish-green dorsolateral stripes and narrow white subspiracular stripe; spiracles marked by prominent yellow spots
Range
west coast from Alaska to California, east to Idaho and Alberta
Habitat
montane coniferous forests
Season
adults fly from March to June
larvae from spring to mid-summer
Food
larvae feed on a variety of coniferous trees: principal hosts are Douglas-fir and Western Hemlock; others include Western Red Cedar, Grand Fir, Amabilis Fir, Subalpine Fir, Sitka Spruce, Engelmann Spruce, White Spruce, Western Larch, Mountain Hemlock, Western White Pine
Life Cycle
one generation per year; overwinters as a pupa in leaf litter; up to 80 eggs are laid singly in the spring on branches and trunks of host trees; larvae emerge in about nine days, and initially feed on the underside of needles; later instars feed openly, preferring foliage of the previous year; most feeding damage occurs in the crown of the tree; larvae complete feeding by early August, drop to the ground, and burrow into the litter and pupate
See Also
Canadian Melanolophia (
Melanolophia canadaria) is similar but lacks the spotted black subterminal line on the forewings, and does not occur west of the great plains and prairies (
compare images of both species)
Hesperumia latipennis has a uniform pale gray forewing with a narrow, sharply dentate median line, and adults fly in summer.
Porcelain Gray (
Protoboarmia porcelaria) and
Small Engrailed (
Ectropis crepuscularia) are similar but lack an ST line composed of several black spots, and lack a distinct round black discal spot on the forewing (
compare images of all three species)
Internet References
pinned adult image plus description, flight season, food plants, similar species (Jeff Miller, Macromoths of Northwest Forests and Woodlands; USGS)
common name reference [Western Carpet; adult] plus description, similar species, habitat, food plants, biology, distribution (Strickland Entomological Museum, U. of Alberta)
live larva image plus food plants, common name reference [Greenstriped Forest Looper; larva], description, biology, distribution, damage (Canadian Forest Service)
distribution in Canada list of provinces (CBIF)
Contributed by
Robin McLeod on 5 February, 2006 - 7:55pm
Additional contributions by
Robert H. BiagiLast updated 28 February, 2018 - 6:31pm