Ottawa (Dunrobin), ON Canada

12 July 2004   9:44PM EST  (top left)
3 July 2002   8:40PM EST  (top right)
18 July 2004   9:18PM EST  (bottom left)
4 July 2002   10:53PM EST  (bottom right)

Acossus centerensis is one of three members of the Cossidae family that have been recorded from the Ottawa area (J.D. Lafontaine, pers. comm., 2001), two of which are illustrated on this web site.  The Cossidae are grouped with the micromoths in the classification of lepidoptera, but in this case, "micromoth" is a misnomer for a group of species that may have wingspans up to 8.5 cm.  For general information on Acossus centerensis, I have relied on Forbes, William T.M., The Lepidoptera of New York and Neighboring States, Primitive Forms, Microlepidoptera, Pyraloids, Bombyces (Ithaca, New York: Cornell University, 1923).

The forewing of Acossus centerensis is patterned in shades of gray, usually darker in the medial area, and covered with fine black lines that give the effect of an overlay of netting.  The hindwing is relatively plain gray, with minimal patterning.  Both wings are slightly translucent.  The thorax is blackish, but with a whitish collar and variably dusted with white.  Forbes indicates a wingspan from 50 to 60 mm.

According to Handfield (1999), the larva of Acossus centerensis tunnels in the trunks and branches of poplar. For my general area, he indicates an adult flight season slightly after mid-May into early August.

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