Damage, symptoms and biologyThe brownlined looper is a common innocuous solitary defoliator.
Mature larva to 35 mm long. Twig mimic. Head, tan with rust mottling, vertex moderately cleft. Body, elongate, colour highly variable from rusty brown (most common) to light tan to dark grey. Prominent subspiracular tubercles on second abdominal segment. Raised pairs of dark tubercles on the dorsum near posterior margin of abdominal segments 2-8.
This species overwinters as a mid-instar larva. Larval feeding resumes in the spring and continues until June. Pupation occurs in June or July; adults emerge in August, mate and lay eggs. Larvae emerge soon after and feed into the fall.
Life cycle (West 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.