Damage, symptoms and biology
The common emerald is a relatively uncommon, innocuous solitary defoliator.
Mature larva to 27 mm long. Twig mimic. Head, brown with black markings, vertex deeply cleft. Body, elongate, smooth, green with dark and white markings at both the anterior and posterior ends; two prominent tubercles on dorsum of first thoracic segment.
This species overwinters as a young larva. Larval feeding resumes in the spring and continues until June. Pupation occurs in June, and adults emerge from June to July.
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.