Ottawa (Dunrobin), ON Canada

23 June 2003   11:01PM EDT  (left)  (female)
23 June 2003   11:07PM EDT  (right)  (male)

My thanks to Dr. J. Donald Lafontaine of Agriculture Canada for confirming my identification of the specimen at right above, which was given to the Canadian National Collection in Ottawa.

Hypena bijugalis is one of about 10 species of Hypena recorded from the Ottawa area, and the only one to exhibit marked sexual dimorphism.

The forewing of the female Hypena bijugalis is grayish brown.  A patch of rich dark brown, outlined in white, begins right at the "shoulder" and extends through the median to the postmedial line, but does not touch the inner margin, where the brown ground colour runs right from the thorax to the pm line.  The postmedial line is slightly wavy, with a sharp tooth about a third of the way down the wing.  The subterminal area comprises more than the outer third of the wing, and is quite white next to the pm line.  The terminal area is shaded brown outside the subterminal line and below the dark brown to black apical dash.  Covell (1983) indicates a wingspan of 2.4 to 3.1 cm.

The forewing of the male Hypena bijugalis is medium to dark brown.  The antemedial, postmedial and subterminal lines are faintly present.  There is a prominent white spot just outside the end of the postmedial line at the inner margin.  A black dot marks the orbicular spot.  There is no apical dash as in the female.

The female Hypena bijugalis is similar to Hypena baltimoralis (Hodges 8442), but H. bijugalis has a much straighter postmedial line located farther from the outer margin and with a single sharp tooth.

The larvae of Hypena bijugalis feed on dogwoods (Cornus alternifolia and C. stolonifera) (Handfield, 1999).  Handfield indicates two generations per year for my general area, with adult flight seasons from late May to mid-July and from later July to the end of August.

I have recorded this species in 2003, on 14 and 23 June.