Syngrapha interrogationis

It is found in northern part of the world including Alaska, Canada, Iceland, Europe, Siberia, the Pacific Northwest region of the United States, and Northeast Asia.

The hindwing is brownish yellow, clouded with darker scales, and with a broad blackish border.

The subspecies transbaikalensis Stgr., from Dauria and East Siberia, is more uniform bluish grey, with very little black suffusion on the forewing and a paler hindwing; this form is also recorded from Estonia by Petersen.

Form rosea Tutt, from Scotland, has a rosy ground colour in place of bluish grey.

Form cinerea [Warren] has the ground color dull ashy grey with scarcely any dark markings, except the subterminal line, and no purplish suffusion; the silvery mark forms a somewhat triangular loop.

Illustration
Fig.9 larvae after last moult