University of Alberta Museums Search

A medium-size (3.0 -3.3 cm wingspan) robust grey or black moth. Form obliquata (Sm.)is the normal form throughout most of Alberta. The forewings of obliquata are medium grey crossed by black antemedian and postmedian lines. The subterminal line consists of a series faint white spots. There is also a faint darker grey median band and reniform spot. The hind wings are dull sooty brown with a dark discal lunule. The nominate form, which is found mainly in the mountains, has the forewings largely suffused with dark black, except for the light grey terminal band and costa. The closely related P. bonuscula is a more even steely blue-grey and lacks complete crosslines. The genitalia of concerta are also very different from those of bonuscula. P. cinerea is much paler grey and flies in fall.

Until recently, the black form concerta and the grey form obliquata were treated as separate species. The striking black form is rare east of the mountains, and most Alberta specimens are the common obliquata form.