Ottawa (Dunrobin), ON Canada

2 July 2004   11:13PM EST  (top)
12 July 2004   11:27PM EST  (bottom)

Eacles imperialis pini, also known as the Pine Imperial Moth, is one of about 10 species of Saturniidae recorded from the Ottawa area (J.D. Lafontaine, pers. comm., 2001).  The Saturniidae, variously termed the Giant Silkworm or Royal Moths include our largest and some of our most spectacular moths.

Eacles imperialis pini has yellow wings, spotted and shaded in brownish purple and pink.  In some specimens, as in the top photo, the shading in the basal area and along the outer margin of the forewing is very heavy, almost solid purple; in others, however, only the antemedial and postmedial lines are solid purple, and the shading is lighter and more pinkish.  The pattern of the hindwing is similar, but typically somewhat less speckled and shaded than the forewing.  On each wing there is a distinct round purple spot in the median.  Specimens I have seen have had wingspans in the order of 10 cm.

According to Handfield (1999), the principal host plant for the larva of Eacles imperialis pini is white pine, but other species of pine may also be hosts. He indicates an adult flight season from the last week of June to late July for my general area.

My records to date for Eacles imperialis pini (each date representing "the night of") are in the table below: