Ottawa (Dunrobin), ON Canada

10 August 2005   10:59PM EST  (top left)
13 August 2005   10:10PM EST  (top right)
15 August 2004   10:27PM EST  (bottom)

Polia purpurissata, also called the Purple Arches moth, is one of several species of Polia recorded from the Ottawa area (J.D. Lafontaine, pers. comm., 2001), three of which are illustrated on this website.

Polia purpurissata has a purplish gray forewing, that can appear quite purple under some lighting conditions.  The double antemedial and postmedial lines are filled with the ground color, and are often somewhat indistinct.  The orbicular, claviform and reniform spots are usually clearly outlined, with filling slightly darker than the ground color of the wing; in some specimens, the claviform spot may be tinged with brown as in the bottom photo.  There is some darker shading toward the costa, especially in the median, and this shading is often reddish brown adjacent to the middle of the reniform spot.  The subterminal line is edged along its inner side with dark brown to blackish shading, evident near the middle of the wing and darkest near the anal angle.  The hindwing is gray-brown with a band of dark shading along the outer margin and a white fringe.  Covell (1984) indicates a wingspan ranging from 4.0 to 5.5 cm for this species.

According to Handfield (1999), the larvae of Polia purpurissata feed on a great variety of plants, including blueberry, alder, birch, maple, spiraea, snowberry, honeysuckle and many others. For my general area, he indicates an adult flight season from about mid-July to the end of August.

My records to date for Polia purpurissata (each date representing "the night of") are in the table below: