Gray spruce looper
Damage, symptoms and biologyThe grey forest looper is a common and occasionally destructive solitary defoliator.
Mature larva to 35 mm long. Head, pale brown with dark herringbone pattern on each lobe. Body, yellow to light brown. Dorsum marked with wavy rusty brown to grey lines and a broken middorsal yellow line. Broad yellow spiracular stripe interrupted by brown patchs surrounding each spiracle. Pair of dark tubercles near posterior margin of each abdominal segment.
This species overwinters in the pupal stage. Adults emerge from June to July; females lay up to 75 eggs on host foliage. Larvae are present from July to mid-September, and pupation occurs in August.
Life cycle (East of the Rockies)
Canadian Forest Service Publications
Diet and feeding behaviour
: Feeds on the leaves of plants.
- Free-living defoliator: Feeds on and moves about freely on foliage.
Information on host(s)
Amabilis fir, balsam fir, black spruce, Engelmann spruce, grand fir, jack pine, Norway spruce, Rocky Mountain Douglas-fir, shore pine, Sitka spruce, subalpine fir, tamarack, western hemlock, western redcedar, white spruce