Brown-lined Looper

The wingspan is about 34 mm. The Brown-lined Looper's ground color ranges from ashy gray, to light brown to dark brown, with numerous brown speckles and variable patches of darker shading between crosslines. Wing edges are scalloped. It has three dark transverse lines on both forewing and hindwing, however the middle line may be obscure. When in a resting posture, with wings spread, the darkest crossline (the PM line) of the hindwing is set lower and dose not line up with the darkest line of the forewing. On the forewing, the basal line is curved convexly and ends on the costa at the basal third. The middle line is broader towards the costa and may be truncated, faded or missing. The third (Postmedial) line has a gentle wave, one point at the lower submedian venule and the third on the median venule.There are discal spots on the hindwing that can be seen when the forewings are open and from the ventral (underside) view. Males have wide, two-sided, pectinate (feathery) antennae. Packard notes of the specimens he studied that the female was "paler ash, less ochreous and the hind wing more deeply scalloped."

The caterpillar is a twig-mimicing looper growing up to 35 mm long. "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 the second abdominal segment. Raised pairs of dark tubercles on the dorsum near posterior margin of abdominal segments 2-8." (Natural Resources Canada ) Adults are observed from June to November (depending on the climate), peaking in late summer. The first instar is born and begins feeding by the fall. It overwinters as a mid-instar larva and resumes feeding in the spring. Pupation occurs in June or July.