Ottawa (Dunrobin), ON Canada

12 July 2002   10:49PM EST  (top left)
12 July 2002   10:04PM EST  (top right)
15 May 2001   10:47PM EST  (bottom left)
16 May 2001   10:12PM EST  (bottom left)

The top two photos are of the same specimen.

Furcula occidentalis is one of several species of Furcula that may occur in my area, several of which are quite similar in appearance.  Compare this moth with Furcula borealis (7936), also illustrated on this web site.  In 2002, some much appreciated help from Jeff Crolla of Toronto and Dr. J. Donald Lafontaine of Agriculture Canada enabled me to sort out three Furcula species among my photographs.

Furcula occidentalis shows a pattern of dark gray and light gray to white characteristic of most Furcula species.  The medial area of the forewing is filled with dark gray, while the basal and subterminal areas are pale gray to white, but lacking the high contrast evident in Furcula borealis (7936).  Basal and terminal lines are represented by rows of black dots.  In the photos above, the subterminal line appears double or triple, and is continuous rather than dotted.  There is also blotch of dark grey at the costal edge just outside the subterminal line.  In the bottom left photo above, it is also possible to see the merest hints of rusty orange adjacent to the dark gray median.

The larvae of Furcula occidentalis feed on willow and poplar.  According to Handfield (1999), there are two generations per season in my general area, with flight periods from early May through June, and from the beginning of July through early August.

I have photographed this species in 2001 on 15 and 16 May; in 2002 on 12 July.