Distribution: Uncommon to rare. Found in Canada from Nova Scotia to Alberta, and in the Yukon. In the US, it is found south to New Jersey, Illinois and Utah.

Seasonality and Size: One brood, flight period in June and July. Wingspan 57-78 mm.

Larva and Host Plants: Foodplants include poplar, willow and birch. Green hornworm with 7 pairs of oblique lateral lines similar to S. gordius except that the horn has a black lateral line.

Field Marks:

Forewing yellowish gray in males, pale gray with yellow tint in females Dark border on outer margin widens towards inner margin Hindwing deep yellow in males, pale yellow in females: both sexes have a wide black border