University of Alberta Museums Search

A large (9.0-13.0 cm wingspan) narrow-winged dull grey moth. The forewings each have four fine horizontal black dashes, the uppermost reaching the apex, and a small diffuse black blotch at the wing base. The hindwings are pale grey with two broad black horizontal bands. The abdomen has a series of large alternating black and white spots along the sides. The much commoner S. vashti averages much smaller than chersis (6.5-10.0 cm wingspan), and has sharper black dashes and better defined banding, and usually has a paler forewing costa, especially on the basal half. Other Alberta Sphinx species have either extensive black on the forewings or very different patterns.

No Alberta data. Elsewhere in Canada, ash (Fraxinus sp.), yellow and white birch (Betula sp.), pincherry (Prunus pennsylvanica), Dogwood (Cornus sp.) and Canada plum (Prunus nigra). Other hosts reported in the literature include, lilac (Syringa), aspen (Populus tremuloides) and Ligustrum. Adults have been observed nectaring at garden flowers at dusk in Saskatchewan.

Primarily a moth of the hardwood forests, chersis is found throughout much of the treed portions of North America south of the boreal forest and extending south into northern Mexico. In Alberta, it has been reported only in the grasslands region, from the South Saskatchewan River south.